Solid-state imaging apparatus, method for manufacturing the same, and electronic device

ABSTRACT

The present technology relates to a solid-state imaging apparatus capable of suppressing occurrence of color mixing, a method for manufacturing the solid-state imaging apparatus, and an electronic device. The solid-state imaging apparatus includes a plurality of pixels arranged in a pixel region. Each of the pixels has: a first optical filter layer disposed on a photoelectric conversion unit; a second optical filter layer disposed on the first optical filter layer; and a separation wall separating at least a part of the first optical filter layer for each of the pixels. Either the first optical filter layer or the second optical filter layer in at least one of the pixels is formed by an infrared cut filter, while the other is formed by a color filter. The present technology can be applied to a CMOS image sensor including a visible light pixel.

TECHNICAL FIELD

The present technology relates to a solid-state imaging apparatus, amethod for manufacturing the solid-state imaging apparatus, and anelectronic device, and particularly to a solid-state imaging apparatuscapable of suppressing occurrence of color mixing, a method formanufacturing the solid-state imaging apparatus, and an electronicdevice.

BACKGROUND ART

Conventionally, a solid-state imaging apparatus that performs imagingusing visible light and imaging using infrared light is known.

In such a solid-state imaging apparatus, an infrared light pixel can beformed, for example, by overlapping red (R) and blue (B) color filters.In this case, all the pixels (visible light pixel and infrared lightpixel) have substantia the same transmittance in an infrared lightregion with a wavelength of 700 nm or more. As a result, color mixingoccurs between the visible light pixel and the infrared light pixel, andcolor separation and S/N deteriorate.

Meanwhile, for example, Patent Document 1 discloses forming an infraredcut filter below a color filter of a visible light pixel. This infraredcut filter is formed by a multilayer interference film obtained byalternately laminating a substance having a high refractive index and asubstance having a low refractive index.

CITATION LIST Patent Document

-   Patent Document 1: Japanese Patent Application Laid-Open No.    2009-18944

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, in the infrared cut filter of Patent Document 1, a transmissiondistribution of infrared light depends on an incident angle, or thenumber of steps increases to raise a difficulty level of a process.

The present technology has been achieved in view of such a situation,and suppresses occurrence of color mixing between pixels while atransmission distribution of infrared light does not depend on anincident angle, and the number of steps does not increase to raise adifficulty level of a process.

Solutions to Problems

A solid-state imaging apparatus of the present technology includes aplurality of pixels arranged in a pixel region. Each of the pixels has:a first optical filter layer disposed on a photoelectric conversionunit; a second optical filter layer disposed on the first optical filterlayer; and a separation wall separating at least a part of the firstoptical filter layer for each of the pixels. Either the first opticalfilter layer or the second optical filter layer in at least one of thepixels is formed by an infrared cut filter, while the other is formed bya color filter.

A method for manufacturing a solid-state imaging apparatus according tothe present technology is a method for manufacturing a solid-stateimaging apparatus including a plurality of pixels arranged in a pixelregion, each of the pixels having: a first optical filter layer disposedon a photoelectric conversion unit; a second optical filter layerdisposed on the first optical filter layer; and a separation wallseparating at least a part of the first optical filter layer for each ofthe pixels, the method including: forming the separation wall; formingthe first optical filter layer; and forming the second optical filterlayer, in which either the first optical filter layer or the secondoptical filter layer in at least one of the pixels is formed by aninfrared cut filter, while the other is formed by a color filter.

An electronic device of the present technology includes a solid-stateimaging apparatus including a plurality of pixels arranged in a pixelregion, in which each of the pixels has: a first optical filter layerdisposed on a photoelectric conversion unit; a second optical filterlayer disposed on the first optical filter layer; and a separation wallseparating at least a part of the first optical filter layer for each ofthe pixels, and either the first optical filter layer or the secondoptical filter layer in at least one of the pixels is formed by aninfrared cut filter, while the other is formed by a color filter.

The present technology includes a plurality of pixels arranged in apixel region. Each of the pixels has: a first optical filter layerdisposed on a photoelectric conversion unit; a second optical filterlayer disposed on the first optical filter layer; and a separation wallseparating at least a part of the first optical filter layer for each ofthe pixels. Either the first optical filter layer or the second opticalfilter layer in at least one of the pixels is formed by an infrared cutfilter, while the other is formed by a color filter.

Effects of the Invention

According to the present technology, occurrence of color mixing betweenpixels can be suppressed. Note that the effects described here are notnecessarily limited, and may be any of the effects described in thepresent disclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view illustrating a configuration example ofa pixel in a conventional solid-state imaging apparatus.

FIG. 2 is a diagram illustrating spectral characteristics of a visiblelight pixel and an infrared light pixel.

FIG. 3 is a block diagram illustrating a configuration example of asolid-state imaging apparatus of the present technology.

FIG. 4 is a cross-sectional view illustrating a configuration example ofa pixel in a solid-state imaging apparatus according to a firstembodiment of the present technology.

FIG. 5 is a view illustrating an example of a planar arrangement of anoptical filter layer.

FIG. 6 is a view illustrating another example of the planar arrangementof the optical filter layer.

FIG. 7 is a diagram illustrating an example of a color material of aninfrared cut filter.

FIG. 8 is a diagram illustrating an example of spectral characteristicsof the infrared cut filter.

FIG. 9 is a flowchart for explaining pixel formation processing.

FIG. 10 is a diagram for explaining a step of pixel formation.

FIG. 11 is a diagram for explaining a step of pixel formation.

FIG. 12 is a diagram for explaining a step of pixel formation.

FIG. 13 is a diagram illustrating spectral characteristics of a visiblelight pixel and an infrared light pixel.

FIG. 14 is a diagram illustrating another example of the spectralcharacteristics of the infrared cut filter.

FIG. 15 is a diagram illustrating still another example of the spectralcharacteristics of the infrared cut filter.

FIG. 16 is a diagram illustrating an example of spectral characteristicsof a dual band pass filter.

FIG. 17 is a cross-sectional view illustrating a configuration exampleof the entire solid-state imaging apparatus.

FIG. 18 is a cross-sectional view illustrating another configurationexample of the pixel.

FIG. 19 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 20 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 21 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 22 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 23 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 24 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 25 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 26 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 27 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 28 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 29 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 30 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 31 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 32 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 33 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 34 is a block diagram illustrating a configuration example of animage processing apparatus.

FIG. 35 is a cross-sectional view illustrating a configuration exampleof a pixel in a solid-state imaging apparatus according to a secondembodiment of the present technology.

FIG. 36 is a view illustrating an example of a planar arrangement of anoptical filter layer.

FIG. 37 is a flowchart for explaining pixel formation processing.

FIG. 38 is a diagram for explaining a step of pixel formation.

FIG. 39 is a cross-sectional view illustrating a configuration exampleof the entire solid-state imaging apparatus.

FIG. 40 is a cross-sectional view illustrating another configurationexample of the pixel.

FIG. 41 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 42 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 43 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 44 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 45 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 46 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 47 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 48 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 49 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 50 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 51 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 52 is a cross-sectional view illustrating still anotherconfiguration example of the pixel.

FIG. 53 is a cross-sectional view illustrating a configuration exampleof a front-illuminated solid-state imaging apparatus to which thepresent technology is applied.

FIG. 54 is a cross-sectional view illustrating another configurationexample of the front-illuminated solid-state imaging apparatus.

FIG. 55 is a cross-sectional view illustrating a configuration exampleof a back-illuminated solid-state imaging apparatus to which the presenttechnology is applied.

FIG. 56 is a diagram illustrating an outline of a configuration exampleof a laminated solid-state imaging apparatus to which the presenttechnology can be applied.

FIG. 57 is a cross-sectional view illustrating a first configurationexample of the laminated solid-state imaging apparatus.

FIG. 58 is a cross-sectional view illustrating a second configurationexample of the laminated solid-state imaging apparatus.

FIG. 59 is a cross-sectional view illustrating a third configurationexample of the laminated solid-state imaging apparatus.

FIG. 60 is a cross-sectional view illustrating another configurationexample of the laminated solid-state imaging apparatus to which thepresent technology can be applied.

FIG. 61 is a plan view illustrating a first configuration example of asolid-state imaging apparatus sharing a plurality of pixels to which thepresent technology can be applied.

FIG. 62 is a cross-sectional view illustrating the first configurationexample of the solid-state imaging apparatus sharing a plurality ofpixels to which the present technology can be applied.

FIG. 63 is a diagram illustrating an example of an equivalent circuit ofa shared pixel unit sharing four pixels.

FIG. 64 is a plan view illustrating a second configuration example ofthe solid-state imaging apparatus sharing a plurality of pixels to whichthe present technology can be applied.

FIG. 65 is a block diagram illustrating a configuration example of anelectronic device of the present technology.

FIG. 66 is a diagram illustrating a use example of using an imagesensor.

FIG. 67 is a diagram illustrating an example of a schematicconfiguration of an endoscopic surgical system.

FIG. 68 is a block diagram illustrating examples of functionalconfigurations of a camera head and a CCU.

FIG. 69 is a block diagram illustrating an example of a schematicconfiguration of a vehicle control system.

FIG. 70 is an explanatory diagram illustrating examples of installationpositions of a vehicle external information detection unit and animaging unit.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present technology will be describedwith reference to the drawings. Note that in the present specificationand the drawings, the same reference numerals are given to constituentelements having substantially the same functional configuration, andredundant explanation is omitted. Furthermore, description will be givenin the following order.

1. Configuration of conventional solid-state imaging apparatus

2. Configuration example of solid-state imaging apparatus of the presenttechnology

3. First embodiment (solid-state imaging apparatus including visiblelight pixel and infrared light pixel)

4. Second embodiment (solid-state imaging apparatus including onlyvisible light pixel)

5. Application example of the present technology

6. Configuration example of electronic device

7. Use example of image sensor

8. Application example to endoscopic surgical system

9. Application example to mobile body

1. Configuration of Conventional Solid-State Imaging Apparatus

FIG. 1 is a cross-sectional view illustrating a configuration example ofa pixel in a conventional solid-state imaging apparatus including avisible light pixel and an infrared light pixel. The solid-state imagingapparatus of FIG. 1 is constituted as, for example, a complementarymetal oxide semiconductor (CMOS) image sensor.

FIG. 1 illustrates a cross-sectional view of a visible light pixel 11and an infrared light pixel 12. The visible light pixel 11 isconstituted as, for example, three types of pixels of a red (R) pixel, agreen (G) pixel, and a blue (B) pixel.

In the visible light pixel 11, a photoelectric conversion unit 22constituted by a photodiode (PD) that receives incident light andperforms photoelectric conversion is formed in a semiconductor substrate21. On the semiconductor substrate 21, an insulating layer (notillustrated) including SiO or the like, a wiring layer (not illustrated)including Cu or Al, and the like are formed. On the insulating layer, acolor filter 23 having spectral characteristics corresponding to each ofthe visible light pixels 11 is formed. On the color filter 23, amicrolens 24 is formed.

Meanwhile, also in the infrared light pixel 12, the semiconductorsubstrate 21, the photoelectric conversion unit 22, an insulating layerand a wiring layer (not illustrated), the color filter 23, and themicrolens 24 are formed similarly to the visible light pixel 11.Moreover, in the infrared light pixel 12, a color filter 25 is formedbetween the color filter 23 and the microlens 24.

In this way, the infrared light pixel 12 is formed by overlapping twocolor filters of R and B, for example.

However, in such a configuration, as illustrated in FIG. 2, all thepixels (R pixel, G pixel, B pixel, and infrared light pixel (IR pixel))have substantially the same transmittance in an infrared light regionwith a wavelength of 700 nm or more. As a result, color mixing occursbetween the visible light pixel and the infrared light pixel, and colorseparation and S/N deteriorate.

Therefore, in the following description, a configuration of asolid-state imaging apparatus suppressing occurrence of color mixingbetween a visible light pixel and an infrared light pixel will bedescribed.

2. Configuration Example of Solid-State Imaging Apparatus of the PresentTechnology

FIG. 3 is a block diagram illustrating a configuration example of asolid-state imaging apparatus of the present technology.

A solid-state imaging apparatus 31 is constituted as a CMOS imagesensor. The solid-state imaging apparatus 31 includes a pixel region(pixel array) 33 in which a plurality of pixels 32 is regularly arrangedin a two-dimensional array on a semiconductor substrate (for example, aSi substrate) (not illustrated) and a peripheral circuit unit.

Each of the pixels 32 includes a photoelectric conversion unit (forexample, a photodiode), and a plurality of pixel transistors (MOStransistors). The plurality of pixel transistors can be constituted by,for example, three transistors of a transfer transistor, a resettransistor, and an amplification transistor. Furthermore, the pluralityof pixel transistors can be constituted by four transistors obtained byadding a selection transistor. Note that an equivalent circuit of a unitpixel is similar to a general equivalent circuit, and therefore detaileddescription thereof will be omitted.

Furthermore, the pixels 32 can be constituted as one unit pixel or ashared pixel structure. In this pixel sharing structure, a plurality ofphotodiodes shares a floating diffusion and a transistor other than thetransfer transistor.

The peripheral circuit unit includes a vertical driving circuit 34, acolumn signal processing circuit 35, a horizontal driving circuit 36, anoutput circuit 37, and a control circuit 38.

The control circuit 38 receives data giving a command of an input clock,an operation mode, or the like, and outputs data of internal informationor the like of the solid-state imaging apparatus 31. Furthermore, thecontrol circuit 38 generates a clock signal and a control signal servingas references for operations of the vertical driving circuit 34, thecolumn signal processing circuit 35, the horizontal driving circuit 36,and the like on the basis of a vertical synchronization signal, ahorizontal synchronization signal, and a master clock. Then, the controlcircuit 38 inputs these signals to the vertical driving circuit 34, thecolumn signal processing circuit 35, the horizontal driving circuit 36,and the like.

The vertical driving circuit 34 is constituted by, for example, a shiftregister. The vertical driving circuit 34 selects pixel driving wiring,supplies a pulse for driving pixels to the selected pixel drivingwiring, and drives the pixels in units of rows. In other words, thevertical driving circuit 34 sequentially selects and scans each of thepixels 32 in the pixel region 33 in a vertical direction in units ofrows. Then, the vertical driving circuit 34 supplies a pixel signalbased on a signal charge generated in accordance with the amount oflight received in a photoelectric conversion unit of each of the pixels32 to the column signal processing circuit 35 through a vertical signalline 39.

The column signal processing circuit 35 is disposed, for example, foreach column of the pixels 32. The column signal processing circuit 35performs signal processing such as removal of a noise for a signaloutput from the pixels 32 in one row for each of the pixel columns.Specifically, the column signal processing circuit 35 performs signalprocessing such as correlated double sampling (CDS) for removing a fixedpattern noise peculiar to the pixels 32, signal amplification, oranalog/digital (A/D) conversion. In an output stage of the column signalprocessing circuit 35, a horizontal selection switch (not illustrated)is connected and disposed between the column signal processing circuit35 and a horizontal signal line 40.

The horizontal driving circuit 36 is constituted by, for example, ashift register. The horizontal driving circuit 36 sequentially selectseach of the column signal processing circuits 35 by sequentiallyoutputting a horizontal scan pulse, and causes each of the column signalprocessing circuits 35 to output a pixel signal to the horizontal signalline 40.

The output circuit 37 performs signal processing on a signalsequentially supplied from each of the column signal processing circuits35 through the horizontal signal line 40, and outputs the processedsignal. For example, the output circuit 37 performs only buffering, orperforms black level adjustment, column variation correction, varioustypes of digital signal processing, and the like.

An input and output terminal 41 exchanges a signal with the outside.

3. First Embodiment

In a solid-state imaging apparatus 31 according to a first embodiment ofthe present technology, as a plurality of pixels 32 arranged in a pixelregion 33, a visible light pixel and an infrared light pixel aredisposed.

FIG. 4 is a cross-sectional view illustrating a configuration example ofa pixel in the solid-state imaging apparatus 31 according to the firstembodiment of the present technology. FIG. 4 illustrates across-sectional view of a visible light pixel 51 and an infrared lightpixel 52 in the solid-state imaging apparatus 31. The visible lightpixel 51 is constituted as, for example, three types of pixels of a red(R) pixel, a green (G) pixel, and a blue (B) pixel.

In the visible light pixel 51, a photoelectric conversion unit 62constituted by a photodiode (PD) that receives incident light andperforms photoelectric conversion is formed on a semiconductor substrate61. On the semiconductor substrate 61, an insulating layer (notillustrated) including SiO or the like, a wiring layer (not illustrated)including Cu or Al, and the like are formed. On the insulating layer, aninfrared cut filter 63 is formed as a first optical filter layer. On theinfrared cut filter 63, a color filter 66 having spectralcharacteristics corresponding to each of the visible light pixels 51 isformed as a second optical filter layer. On the color filter 66, amicrolens 67 is formed.

In the infrared light pixel 52, the photoelectric conversion unit 62 isformed on the semiconductor substrate 61. On the semiconductor substrate61, an insulating layer, a wiring layer, and the like (not illustrated)are formed. On the insulating layer, for example, a blue (B) colorfilter 64 is formed as a first optical filter layer. On the color filter64, for example, the red (R) color filter 66 is formed as a secondoptical filter layer. On the color filter 66, the microlens 67 isformed. Each of the color filter 64 and the color filter 66 is formed bya color filter that transmits infrared light, and a combination of thetwo color filters can reduce a transmittance of light in a visible lightregion.

Furthermore, each of the pixels (visible light pixel 51 and infraredlight pixel 52) has a separation wall 65 separating the first opticalfilter layer for each of the pixels. The separation wall 65 includes ametal film 65 a including W, Al, or the like, and a Si oxide film 65 bincluding SiO2, SiN, or the like. In the example of FIG. 4, the heightof the separation wall 65 is the same as the height of the first opticalfilter layer (infrared cut filter 63 or color filter 64).

Here, a planar arrangement of pixels will be described.

FIG. 5 is a diagram illustrating an example of planar arrangements ofthe first and second optical filter layers in the visible light pixel 51and the infrared light pixel 52.

The lower part of FIG. 5 illustrates an arrangement of the first opticalfilter layer in the visible light pixel 51 and the infrared light pixel52. The upper part of FIG. 5 illustrates an arrangement of the secondoptical filter layer in the visible light pixel 51 and the infraredlight pixel 52.

The arrangement of the second optical filter layer indicates that one ofthe G pixels in the Bayer array is replaced by an infrared light pixel(IR pixel) in the example of FIG. 5. Note that the first optical filterlayer other than the IR pixel is an infrared cut filter in the lowerpart of FIG. 5 and that the second optical filter layer other than theIR pixel is a color filter of an R, G, or B pixel in the upper part ofFIG. 5.

FIG. 6 is a diagram illustrating another example of the planararrangements of the first and second optical filter layers in thevisible light pixel 51 and the infrared light pixel 52.

Similarly to the example of FIG. 5, the lower part of FIG. 6 illustratesan arrangement of the first optical filter layer in the visible lightpixel 51 and the infrared light pixel 52. The upper part of FIG. 6illustrates an arrangement of the second optical filter layer in thevisible light pixel 51 and the infrared light pixel 52.

In the example of FIG. 6, G pixels are arranged in a checkerboardpattern, and G pixels, B pixels, and infrared light pixels (IR pixels)are regularly arranged in the remaining areas.

According to the planar arrangements of FIG. 6, resolution can beimproved as compared with the planar arrangements of FIG. 5.

Furthermore, the infrared cut filter 63 of the visible light pixel 51includes an organic material to which a near infrared absorptive dye isadded as an organic color material. Examples of the near infraredabsorptive dye include a pyrrolopyrrole dye, a copper compound, acyanine-based dye, a phthalocyanine-based compound, an imonium-basedcompound, a thiol complex-based compound, a transition metal oxide-basedcompound, a squarylium-based dye, a naphthalocyanine-based dye, aquaterrylene-based dye, a dithiol metal complex-based dye, a croconiumcompound, and the like. In the present embodiment, the pyrrolopyrroledye illustrated in the chemical formula of FIG. 7 is preferably used.

In FIG. 7, R1 a and R1 b each independently represent an alkyl group, anaryl group, or a heteroaryl group. R2 and R3 each independentlyrepresent a hydrogen atom or a substituent, and at least one of thesegroups represents an electron withdrawing group. R2 and R3 may be bondedto each other to form a ring. R4 represents a hydrogen atom, an alkylgroup, an aryl group, a heteroaryl group, a substituted boron atom, or ametal atom and may be bonded covalently or coordinately to at least oneof R1 a, R1 b, and R3.

FIG. 8 is a diagram illustrating an example of spectral characteristicsof the infrared cut filter 63.

As illustrated in FIG. 8, the infrared cut filter 63 has such spectralcharacteristics that the transmittance is 20% or less in a wavelengthregion of 700 nm or more, and particularly has an absorption maximumwavelength in a wavelength region near 850 nm.

Note that the infrared cut filter 63 of the visible light pixel 51 mayinclude an organic material to which an inorganic color material isadded instead of an organic color material.

(Regarding Flow of Pixel Formation)

Next, a flow of pixel formation according to the present embodiment willbe described with reference to FIGS. 9 to 12. FIG. 9 is a flowchart forexplaining pixel formation processing, and FIGS. 10 to 12 arecross-sectional views illustrating steps of pixel formation.

Hereinafter, processing after the photoelectric conversion unit 62 isformed on the semiconductor substrate 61 will be described.

In step S11, as illustrated in the upper part of FIG. 10, a metal film65 a′ and a Si oxide film 65 b′ are formed on the semiconductorsubstrate 61.

In step S12, the separation wall 65 is formed. Specifically, asillustrated in the upper part of FIG. 10, a photoresist 71 is applied toa region where the separation wall 65 is to be formed, exposed anddeveloped by photolithography, and further dry etched to form theseparation wall 65 as illustrated in the middle part of FIG. 10.

At this time, a Si oxide film may be further formed on surfaces of thesemiconductor substrate 61 and the separation wall 65.

In step S13, coating is performed with an infrared cut filter material63′ by spin coating. As a result, as illustrated in the lower part ofFIG. 10, a film of the infrared cut filter material 63′ is formed(embedded) in a region surrounded by the separation wall 65.

In step S14, the infrared cut filter 63 is formed as the first opticalfilter layer of the visible light pixel 51. For example, in a case wherethe infrared cut filter material 63′ does not have photolithographyperformance, a photoresist 72 is applied onto the infrared cut filtermaterial 63′, and as illustrated in the upper part of FIG. 11, thephotoresist 72 is removed from the region of the infrared light pixel52. In addition, by performing dry etching, the infrared cut filtermaterial 63′ is removed from the region of the infrared light pixel 52.Furthermore, in a case where the infrared cut filter material 63′ hasphotolithography performance, the photoresist 72 is not applied onto theinfrared cut filter material 63′, and the infrared cut filter material63′ is directly exposed and developed to remove the infrared cut filtermaterial 63′ from the region of the infrared light pixel 52. As aresult, as illustrated in the middle part of FIG. 11, the infrared cutfilter 63 of the visible light pixel 51 is formed.

In step S15, as illustrated in the lower part of FIG. 11, for example, ablue (B) color filter is formed as a first optical filter layer of theinfrared light pixel 52.

In step S16, as illustrated in the upper part of FIG. 12, the colorfilter 66 as a second layer is formed as a second optical filter layerfor each of the pixels. For example, a red (R) color filter is formed asthe second optical filter layer of the infrared light pixel 52.

Then, in step S17, as illustrated in the lower part of FIG. 12, themicrolens 67 is uniformly formed for each of the pixels.

In this way, the visible light pixel 51 and the infrared light pixel 52are formed.

According to the above configuration and processing, the infrared cutfilter 63 is formed as the first optical filter layer in the visiblelight pixel 51, and the color filter 66 is formed as the second opticalfilter layer. As a result, as illustrated in FIG. 13, an R pixel, a Gpixel, and a B pixel have such spectral characteristics that atransmittance is low in an infrared light region at a wavelength ofabout 850 nm, while an infrared light pixel (IR pixel) has such spectralcharacteristics that a high transmittance is maintained in the infraredlight region. As a result, occurrence of color mixing between thevisible light pixel and the infrared light pixel can be suppressed, andcolor separation and deterioration of S/N can be suppressed.

Furthermore, the separation wall 65 separating the first optical filterlayer for each of the pixels is formed in each of the pixels, andtherefore occurrence of color mixing between the visible light pixel andthe infrared light pixel can be more reliably suppressed.

Conventionally, an infrared cut filter including an organic material isliable to be damaged on a side surface thereof during processing, andvariation in shape may be large. Meanwhile, in the present embodiment,the infrared cut filter 63 is processed while being surrounded by theseparation walls 65, and therefore processing can be performed withoutdamaging the side surface of the infrared cut filter 63.

Moreover, when the first optical filter is formed, the first opticalfilter can be formed so as to have a desired thickness due to the heightof the separation wall 65.

Furthermore, the infrared cut filter 63 includes an organic material towhich an organic or inorganic color material is added, and therefore theinfrared cut filter 63 can uniformly contain the color material. As aresult, unlike the infrared cut filter of Patent Document 1, thetransmission distribution of infrared light does not depend on theincident angle, and a constant transmittance can be obtained regardlessof the incident angle of infrared light. Furthermore, the number ofsteps does not increase, and therefore an increase in difficulty of theprocess can be avoided.

Moreover, two optical filter layers are formed in each of the pixels.Therefore, the height of the entire optical filter layers is easilyequalized, and occurrence of application unevenness can be suppressedwhen a microlens material is applied.

(Another Example of Spectral Characteristics of Infrared Cut Filter)

Note that, in the above-described example, the infrared cut filter 63may have such spectral characteristics that an absorption maximumwavelength is present in a wavelength region around 850 nm. However, thetransmittance only needs to be 20% or less in a wavelength region of 700nm or more.

For example, as illustrated in FIG. 14, the infrared cut filter 63 mayhave such spectral characteristics that the transmittance is 20% or lessin the entire wavelength region of 750 nm or more. Alternatively, asillustrated in FIG. 15, an absorption maximum wavelength may be presentin a wavelength region around 950 nm.

Particularly, by determining the absorption maximum wavelength dependingon a color material to be added to the infrared cut filter 63, theinfrared cut filter 63 can be an optical filter that selectively absorbsinfrared light in a predetermined wavelength region in the visible lightpixel 51. The absorption maximum wavelength can be determined dependingon a use of a solid-state imaging apparatus 1.

(Measures Against Flare and Ghost Caused by Reflection of InfraredLight)

In a camera system including a solid-state imaging apparatus having avisible light pixel and an infrared light pixel, infrared light in aspecific wavelength region needs to be incident on a chip constitutingthe solid-state imaging apparatus. Therefore, in such a camera system, adual band pass filter having spectral characteristics illustrated inFIG. 16 is disposed between a camera lens and the solid-state imagingapparatus as an infrared cut filter.

The infrared cut filter having spectral characteristics illustrated inFIG. 16 transmits infrared light having a wavelength of 800 to 900 nm inaddition to visible light.

In a camera system including a solid-state imaging apparatus having noinfrared light pixel, a filter that cuts infrared light in allwavelength regions is used as an infrared cut filter. Therefore,infrared light is not incident on a chip. Meanwhile, in a camera systemincluding a solid-state imaging apparatus having an infrared lightpixel, infrared light in a specific wavelength region is incident on achip. Therefore, the infrared light is reflected by a portion other thanthe pixel, and lare and ghost thereby occur to deteriorate S/N.

FIG. 17 is a cross-sectional view illustrating a configuration exampleof the entire solid-state imaging apparatus 31.

A first configuration example of the solid-state imaging apparatus 31 isillustrated in the upper part of FIG. 17, and a second configurationexample of the solid-state imaging apparatus 31 is illustrated in thelower part of FIG. 17.

On the right side of the drawing, a part of the pixel region 33 in whichpixels are arranged is illustrated. In FIG. 17, the right direction is adirection toward the center of the pixel region 33, and the leftdirection is a direction toward the outside (end portion) of the entirechip.

In the drawing, on the left side of the pixel region 33 (around thepixel region 33), a circuit unit 81 constituting a peripheral circuit isdisposed. Furthermore, in the drawing, on the left end (end portion ofthe chip), a connection hole 82 in which a conductor to be connected toan electrode pad formed on the chip is embedded is disposed.

Here, in the first configuration example in the upper part of FIG. 17,the color filter 66 is formed even in a region other than the pixelregion 33, specifically, even in a region outside the circuit unit 81.As a result, it is possible to suppress reflection of visible lightcorresponding to a predetermined color and transmission of the light tothe circuit unit 81.

However, in the first configuration example, in a case where infraredlight in a specific wavelength region is incident on the chip, flare andghost may occur by reflection of the infrared light by a portion otherthan the pixel, and S/N may deteriorate.

Meanwhile, in the second configuration example in the lower part of FIG.17, the infrared cut filter 63 is formed even in a region other than thepixel region 33, specifically, even in the entire chip region. As aresult, it is possible to suppress reflection of the infrared light by aportion other than the pixel. Therefore, occurrence of flare and ghostcan be suppressed, and deterioration of S/N can be further suppressed.

Moreover, a step outside the pixel region 33 can be reduced by formingthe infrared cut filter 63 in the entire chip region. Therefore,occurrence of application unevenness can be suppressed when a colorfilter material or a microlens material is applied.

(Another Configuration of Separation Wall)

In the above-described example, the separation wall separating the firstoptical filter layer for each of the pixels includes the metal film 65 aincluding W, Al, or the like, and the Si oxide film 65 b including SiO2,SiN, or the like.

However, the material of the separation wall is not limited thereto. Forexample, as illustrated in FIG. 15, a separation wall 91 may includeonly a metal film including W, Al, or the like. Alternatively, asillustrated in FIG. 19, a separation wall 92 may include only a Si oxidefilm including SiO2, SiN, or the like.

Furthermore, as illustrated in FIG. 20, a separation wall 93 may includean organic resin having a refractive index equal to or lower than thatof each of the color filters 64 and 66. The separation wall 93 mayinclude an organic resin containing a filler. The separation wall 93desirably has a refractive index of 1.5 or less.

Furthermore, in the above-described example, the height of theseparation wall separating the first optical filter layer for each ofthe pixels is the same as the height of the first optical filter layer(infrared cut filter 63 or color filter 64).

However, the height of the separation wall is not limited thereto. Forexample, as illustrated in FIG. 21, the height of a separation wall 94may be about ⅓ to ¼ of the height of the first optical filter layer. Inthis case, the height of the separation wall 94 is desirably at least100 nm or more.

Furthermore, as illustrated in FIG. 22, the height of a separation wall95 may be the same as the total height of the first optical filter layerand the second optical filter layer (color filter 66). Alternatively, asillustrated in FIG. 23, the height of a separation wall 96 may be higherthan the total height of the first optical filter layer and the secondoptical filter layer to reach the microlens 67.

Moreover, in addition to the above-described configuration, each of thepixels may have a PD separation wall separating the photoelectricconversion unit 62 for each of the pixels. In this case, the PDseparation wall can be formed integrally with the separation wall 65 andthe like in the above-described configuration.

For example, as illustrated in FIG. 24, a separation wall 97 separatingthe photoelectric conversion unit 62 and the first optical filter layerfor each of the pixels is disposed. A portion of the separation wall 97corresponding to the PD separation wall includes a Si oxide filmincluding SiO2, SiN, or the like.

Furthermore, as illustrated in FIG. 25, a separation wall 98 separatingthe photoelectric conversion unit 62 and the first optical filter layerfor each of the pixels is disposed. A portion of the separation wall 98corresponding to the PD separation wall includes a metal film includingW, Al, or the like.

In this way, by further disposing the PD separation wall separating thephotoelectric conversion unit 62 for each of the pixels, occurrence ofcolor mixing between the pixels can be more reliably suppressed.

(Another Configuration of Optical Filter Layer)

In the above-described example, in the visible light pixel 51, theinfrared cut filter 63 is formed as the first optical filter layer, andthe color filter 66 is formed as the second optical filter layer.

Such a configuration is preferable in a case where the infrared cutfilter 63 is processed by dry etching. However, conversely, asillustrated in FIG. 26, of course, the color filter 66 can be formed asthe first optical filter layer, and the infrared cut filter 63 can beformed as the second optical filter layer.

Furthermore, in the above-described example, in the infrared light pixel52, the first optical filter layer and the second optical filter layerare formed by overlapping color filters of different types (differentcolors).

Each of the two color filters (first optical filter layer and secondoptical filter layer) in the infrared light pixel 52 only needs to havesuch spectral characteristics that the transmittance is 20% or less in awavelength region of 400 to 700 nm and 80% in a wavelength region of 700nm or more. As illustrated in FIG. 27, the two color filters may beformed by overlapping color filters 101 and 102 of the same type (samecolor).

Modification Example

In the above-described example, the color filter 66 as the secondoptical filter layer is formed directly on the first optical filterlayer.

The present invention is not limited thereto. As illustrated in FIG. 28,an organic film 111 may be formed between the first optical filter layer(infrared cut filter 63 and color filter 64) and the second opticalfilter layer (color filter 66). The organic film 111 includes, forexample, an acrylic resin, a styrene resin, siloxane, or the like.Similarly, as illustrated in FIG. 29, an inorganic film 121 may beformed between the first optical filter layer (infrared cut filter 63and color filter 64) and the second optical filter layer (color filter66). The organic film 111 includes, for example, SiO2 or the like.

The organic film 111 of FIG. 28 and the inorganic film 121 of FIG. 29function as planarizing films of the first optical filter layer and alsofunction as protective layers of the infrared cut filter 63.

Furthermore, in a case where an inorganic film is formed between thefirst optical filter layer and the second optical filter layer, theinorganic film 131 may be formed in such a manner as illustrated in FIG.30 from a viewpoint of protection of the infrared cut filter 63. Theinorganic film 131 is formed so as to cover an upper surface and a sidesurface of the infrared cut filter 63 in the first optical filter layer.

Moreover, as described with reference to FIG. 26, in a case where thecolor filter 66 is formed as the first optical filter layer and theinfrared cut filter 63 or the color filter 64 is formed as the secondoptical filter layer, such a structure as illustrated in FIG. 31 may beadopted. In FIG. 31, an inorganic film 141 is formed as the firstoptical filter layer on an upper surface of the color filter 66 (betweenthe first optical filter layer and the second optical filter layer).Moreover, an inorganic film 142 is formed so as to cover an uppersurface and a side surface of the infrared cut filter 63 in the secondoptical filter layer.

Furthermore, as illustrated in FIG. 32, an organic film 151 may beformed between the second optical filter layer (color filter 66) and themicrolens 67. The organic film 151 includes, for example, an acrylicresin, a styrene resin, siloxane, or the like. Similarly, as illustratedin FIG. 33, an inorganic film 161 may be formed between the secondoptical filter layer (color filter 66) and the microlens 67. Theinorganic film 161 includes, for example, SiO2 or the like.

Note that it is also possible to combine the structure of FIG. 32 or 33with each of the structures of FIGS. 28 to 31.

(Configuration Example of Image Processing Apparatus)

Next, a configuration example of an image processing apparatus includingthe solid-state imaging apparatus of the present technology will bedescribed with reference to FIG. 34.

An image processing apparatus 301 illustrated in FIG. 34 includes anoptical lens 311, a filter 312, an image sensor 313, an IR lightemitting unit 314, an image processing unit 315, and a control unit 316.FIG. 34 illustrates an embodiment in a case where the above-describedsolid-state imaging apparatus 31 of the present technology is disposedin the image processing apparatus as the image sensor 313.

The optical lens 311 is constituted as a monocular single focal lens,condenses light from a subject, and causes the condensed light to beincident on the image sensor 313 via the filter 312. The filter 312 hassuch spectral characteristics that a transmission band is present in awavelength region of near infrared light together with in a visiblelight region. The image sensor 313 images a subject and supplies avisible light image (RGB image) and an infrared light image (IR image)to the image processing unit 315 at the same time.

The RGB image is an image generated by pixel output of the visible lightpixel included in the image sensor 313. The IR image is an imagegenerated by pixel output of the infrared light pixel included in theimage sensor 313.

The IR light emitting unit 314 emits infrared light at a timing when theimage sensor 313 performs imaging, thereby irradiating a subject withinfrared light.

The image processing unit 315 performs predetermined image processingusing the RGB image and IR image supplied from the image sensor 313.

The control unit 316 controls the overall operation of the imageprocessing apparatus 301, such as light emission of the IR lightemitting unit 314 and image processing of the image processing unit 315.

Examples of the image processing using the RGB image and the IR imageinclude face authentication, iris authentication, motion capture, andthe like.

In a case where face authentication is performed, authentication isperformed using not only a face appearing on the RGB image but also aface appearing on the IR image. Therefore, highly accurate faceauthentication can be achieved without being affected by a lightingenvironment.

In a case where iris authentication is performed, an iris patternobtained by reflection of light emitted from the IR light emitting unit314 by an iris is acquired as the IR image, and the IR image isregistered/verified to achieve iris authentication.

In a case where motion capture is performed, light emitted from the IRlight emitting unit 314 and reflected by a reflection marker is acquiredas the IR image, and coordinates of the reflection marker are calculatedto achieve motion capture.

As described above, the image sensor to which the present technology isapplied can be applied to various applications using the IR image.

In the above, the configuration of the solid-state imaging apparatusincluding a visible light pixel and an infrared light pixel has beendescribed.

By the way, in a case where infrared light is incident on a solid-stateimaging apparatus including only a visible light pixel, photoelectricconversion is also performed, and therefore S/N deteriorates due tocolor mixing of infrared light. Therefore, generally, an infrared cutfilter that cuts infrared light is disposed on a sealing glass of apackage.

However, in a case where light that has passed through the infrared cutfilter is reflected by a light receiving surface and returns to theinfrared cut filter side, the light may be further reflected by theinfrared cut filter and may be incident on a peripheral pixel. As aresult, ghost may occur in an obtained image.

Therefore, in the following description, a configuration of asolid-state imaging apparatus that suppresses occurrence of ghost whilecutting infrared light will be described.

4. Second Embodiment

In a solid-state imaging apparatus 31 according to a second embodimentof the present technology, only visible light pixels are disposed as aplurality of pixels 32 arranged in a pixel region 33.

FIG. 35 is a cross-sectional view illustrating a configuration exampleof a pixel in the solid-state imaging apparatus 31 according to thesecond embodiment of the present technology. FIG. 35 illustrates across-sectional view of a visible light pixel 51 in the solid-stateimaging apparatus 31. The visible light pixel 51 is constituted as, forexample, three types of pixels of a red (R) pixel, a green (G) pixel,and a blue (B) pixel.

As in the first embodiment, in the visible light pixel 51, aphotoelectric conversion unit 62 constituted by a photodiode (PD) thatreceives incident light and performs photoelectric conversion is formedon a semiconductor substrate 61. On the semiconductor substrate 61, aninsulating layer (not illustrated) including SiO or the like, a wiringlayer (not illustrated) including Cu or Al, and the like are formed. Onthe insulating layer, an infrared cut filter 63 is formed as a firstoptical filter layer. On the infrared cut filter 63, a color filter 66having spectral characteristics corresponding to each of the visiblelight pixels 51 (R, G, and B pixels) is formed as a second opticalfilter layer. On the color filter 66, a microlens 67 is formed.

Furthermore, each of the pixels (visible light pixels 51) has aseparation wall 65 separating the first optical filter layer for each ofthe pixels. The separation wall 65 includes a metal film 65 a includingW, Al, or the like, and a Si oxide film 65 b including SiO2, SiN, or thelike. In the example of FIG. 35, the height of the separation wall 65 isthe same as the height of the first optical filter layer (infrared cutfilter 63).

Here, a planar arrangement of pixels will be described.

FIG. 36 is a diagram illustrating an example of planar arrangements ofthe first and second optical filter layers in the visible light pixel51.

The lower part of FIG. 36 illustrates an arrangement of the firstoptical filter layer in the visible light pixel 51. The upper part ofFIG. 36 illustrates an arrangement of the second optical filter layer inthe visible light pixel 51.

The arrangement of the second optical filter layer indicates that the R,G, and B pixels are arranged in a Bayer array in the example of FIG. 36.In other words, in the lower part of FIG. 36, the first optical filterlayer is an infrared cut filter, and in the upper part of FIG. 36, thesecond optical filter layer is a color filter of R, G, and B pixels.

Note that a color filter of any color other than the above-describedthree colors of R, G, and B may be used as a color filter of the visiblelight pixel 51. For example, a cyan, magenta, or yellow color filter maybe used, or a transparent color filter may be used.

Furthermore, also in the present embodiment, as in the first embodiment,the infrared cut filter 63 of the visible light pixel 51 preferablyincludes an organic material to which a near infrared absorptive dye isadded as an organic color material, and the pyrrolopyrrole dyeillustrated in the chemical formula of FIG. 7 is preferably used.

Moreover, in the present embodiment, the spectral characteristics of theinfrared cut filter 63 are also similar to those in the firstembodiment.

(Regarding Flow of Pixel Formation)

Next, a flow of pixel formation according to the present embodiment willbe described with reference to FIGS. 37 and 38. FIG. 37 is a flowchartfor explaining pixel formation processing, and FIG. 38 is across-sectional view illustrating steps of pixel formation.

Note that processing in steps S21 and S22 in the flowchart of FIG. 37 issimilar to processing in steps S11 and S12 in the flowchart of FIG. 9(steps in the upper and middle parts of FIG. 10), and thereforedescription thereof will be omitted.

In step S23, coating is performed with an infrared cut filter material63′ (FIG. 10) by spin coating. As illustrated in the lower part of FIG.10, a film of the infrared cut filter material 63′ is formed (embedded)in a region surrounded by the separation wall 65. As a result, theinfrared cut filter 63 is formed as the first optical filter layer ofthe visible light pixel 51.

Subsequently, in step S24, as illustrated in the upper part of FIG. 38,the color filter 66 as a second layer is formed as a second opticalfilter layer for each of the pixels.

Then, in step S25, as illustrated in the lower part of FIG. 38, themicrolens 67 is uniformly formed for each of the pixels.

In this way, the visible light pixel 51 is formed.

According to the above configuration and processing, the infrared cutfilter 63 is formed as the first optical filter layer in the visiblelight pixel 51, and the color filter 66 is formed as the second opticalfilter layer. As a result, as illustrated in FIG. 13, an R pixel, a Gpixel, and a B pixel have such spectral characteristics that thetransmittance is low in an infrared light region at a wavelength ofabout 850 nm.

As a result, it is possible not to dispose an infrared light cut filteron a sealing glass of a package, and as a result, the height of thepackage can be reduced. Moreover, by disposing no infrared light cutfilter on the sealing glass of the package, occurrence of ghost due tofurther reflection of light reflected on a light receiving surface bythe infrared cut filter can be suppressed.

Furthermore, the separation wall 65 separating the first optical filterlayer for each or the pixels is formed in each of the pixels. Therefore,occurrence of color mixing between visible light pixels can besuppressed more reliably.

In addition, in the present embodiment, the infrared cut filter 63 isprocessed while being surrounded by the separation walls 65, andtherefore processing can be performed without damaging the side surfaceof the infrared cut filter 63.

Moreover, when the first optical filter is formed, the first opticalfilter can be formed so as to have a desired thickness due to the heightof the separation wall 65.

Furthermore, the infrared cut filter 63 includes an organic material towhich an organic or inorganic color material is added, and therefore theinfrared cut filter 63 can uniformly contain the color material. As aresult, unlike the infrared cut filter of Patent Document 1, thetransmission distribution of infrared light does not depend on theincident angle, and a constant transmittance can be obtained regardlessof the incident angle of infrared light. Furthermore, the number ofsteps does not increase, and therefore an increase in difficulty of theprocess can be avoided.

Moreover, two optical filter layers are formed in each of the pixels.Therefore, the height of the entire optical filter layers is easilyequalized, and occurrence of application unevenness can be suppressedwhen a microlens material is applied.

(Measures Against Flare and Ghost Caused by Reflection of InfraredLight)

The configuration of the entire solid-state imaging apparatus 31 of thepresent embodiment can also adopt a similar configuration to that of thefirst embodiment.

FIG. 39 is a cross-sectional view illustrating a configuration exampleof the entire solid-state imaging apparatus 31.

A first configuration example of the solid-state imaging apparatus 31 isillustrated in the upper part of FIG. 39, and a second configurationexample of the solid-state imaging apparatus 31 is illustrated in thelower part of FIG. 39.

On the right side of the drawing, a part of the pixel region 33 in whichpixels are arranged is illustrated. In FIG. 39, the right direction is adirection toward the center of the pixel region 33, and the leftdirection is a direction toward the outside (end portion) of the entirechip.

In the drawing, on the left side of the pixel region 33 (around thepixel region 33), a circuit unit 81 constituting a peripheral circuit isdisposed. Furthermore, in the drawing, on the left end (end portion ofthe chip), a connection hole 82 in which a conductor to be connected toan electrode pad formed on the chip is embedded is disposed.

Here, in the first configuration example in the upper part of FIG. 39,the color filter 66 is formed even in a region other than the pixelregion 33, specifically, even in a region outside the circuit unit 81.As a result, it is possible to suppress reflection of visible lightcorresponding to a predetermined color and transmission of the light tothe circuit unit 81.

However, in the first configuration example, in a case where infraredlight in a specific wavelength region is incident on the chip, flare andghost may occur by reflection of the infrared light by a portion otherthan the pixel, and S/N may deteriorate.

Meanwhile, in the second configuration example in the lower part of FIG.39, the infrared cut filter 63 is formed even in a region other than thepixel region 33, specifically, even in the entire chip region. As aresult, it is possible to suppress reflection of the infrared light by aportion other than the pixel. Therefore, occurrence of flare and ghostcan be suppressed, and deterioration of S/N can be further suppressed.

Moreover, a step outside the pixel region 33 can be reduced by formingthe infrared cut filter 63 in the entire chip region. Therefore,occurrence of application unevenness can be suppressed when a colorfilter material or a microlens material is applied.

(Another Configuration of Separation Wall)

As in the first embodiment, also in the present embodiment, theseparation wall separating the first optical filter layer for each ofthe pixels includes the metal film 65 a including W, Al, or the like,and the Si oxide film 65 b including SiO2, SiN, or the like.

However, the material of the separation wall is not limited thereto. Forexample, as illustrated in FIG. 40, the separation wall 91 may includeonly a metal film including N, Al, or the like. Alternatively, asillustrated in FIG. 41, the separation wall 92 may include only a Sioxide film including SiO2, SiN, or the like.

Furthermore, as illustrated in FIG. 42, the separation wall 93 mayinclude an organic resin having a refractive index equal to or lowerthan that of the color filter 66. The separation wall 93 may include anorganic resin containing a filler. The separation wall 93 desirably hasa refractive index of 1.5 or less.

Furthermore, in the above-described example, the height of theseparation wall separating the first optical filter layer for each ofthe pixels is the same as the height of the first optical filter layer(infrared cut filter 63).

However, the height of the separation wall is not limited thereto. Forexample, as illustrated in FIG. 43, the height of a separation wall 94may be about ⅓ to ¼ of the height of the first optical filter layer. Inthis case, the height of the separation wall 94 is desirably at least100 nm or more.

Furthermore, as illustrated in FIG. 44, the height of a separation wall95 may be the same as the total height of the first optical filter layerand the second optical filter layer (color filter 66). Alternatively, asillustrated in FIG. 45, the height of a separation wall 96 may be higherthan the total height of the first optical filter layer and the secondoptical filter layer to reach the microlens 67.

Moreover, in addition to the above-described configuration, each of thepixels may have a PD separation wall separating the photoelectricconversion unit 62 for each of the pixels. In this case, the PDseparation wall can be formed integrally with the separation wall 65 andthe like in the above-described configuration.

For example, as illustrated in FIG. 46, a separation wall 97 separatingthe photoelectric conversion unit 62 and the first optical filter layerfor each of the pixels is disposed. A portion of the separation wall 97corresponding to the PD separation wall includes a Si oxide filmincluding SiO2, SiN, or the like.

Furthermore, as illustrated in FIG. 47, a separation wall 98 separatingthe photoelectric conversion unit 62 and the first optical filter layerfor each of the pixels is disposed. A portion of the separation wall 98corresponding to the PD separation wall includes a metal film includingW, Al, or the like.

In this way, by further disposing the PD separation wall separating thephotoelectric conversion unit 62 for each of the pixels, occurrence ofcolor mixing between the pixels can be more reliably suppressed.

(Another Configuration of Optical Filter Layer)

As in the first embodiment, also in the present embodiment, in thevisible light pixel 51, the infrared cut filter 63 is formed as thefirst optical filter layer, and the color filter 66 is formed as thesecond optical filter layer.

However, conversely, as illustrated in FIG. 48, of course, the colorfilter 66 can be formed as the first optical filter layer, and theinfrared cut filter 63 can be formed as the second optical filter layer.

Modification Example

As in the first embodiment, also in the present embodiment, the colorfilter 66 as the second optical filter layer is formed directly on thefirst optical filter layer.

The present invention is not limited thereto. As illustrated in FIG. 49,an organic film 111 may be formed between the first optical filter layer(infrared cut filter 63) and the second optical filter layer (colorfilter 66). Similarly, as illustrated in FIG. 50, an inorganic film 121may be formed between the first optical filter layer (infrared cutfilter 63) and the second optical filter layer (color filter 66).

Moreover, as illustrated in FIG. 51, an organic film 151 may be formedbetween the second optical filter layer (color filter 66) and themicrolens 67. Similarly, as illustrated in FIG. 52, an inorganic film161 may be formed between the second optical filter layer (color filter66) and the microlens 67.

Note that it is also possible to combine the structure of FIG. 51 or 52with each of the structures of FIGS. 49 and 50.

5. Application Example of the Present Technology

The present technology can be applied not only to a CMOS image sensorbut also to a charge coupled device (CCD) image sensor.

In a case where the present technology is applied to a CMOS imagesensor, the CMOS image sensor can adopt a front-illuminated structure ora back-illuminated structure.

(Structure Example of Front-Illuminated Solid-State Imaging Apparatus)

FIG. 53 is a cross-sectional view illustrating a structure example of afront-illuminated solid-state imaging apparatus.

As illustrated in FIG. 53, in the front-illuminated solid-state imagingapparatus, a photodiode (PD) 530 is formed on a semiconductor substrate520 for each of pixels 510. The PD 530 receives incident light incidentfrom a front (upper surface in the drawing) side of the semiconductorsubstrate 520. On the semiconductor substrate 520, a wiring layer 540 isdisposed.

The wiring layer 540 includes wiring 541 and an insulating layer 542 andis formed such that the wiring 541 is electrically connected to eachelement in the insulating layer 542. The wiring layer 540 is a so-calledmultilayered wiring layer and formed by alternately laminating aninterlayer insulating film constituting the insulating layer 542 and thewiring 541 a plurality of times.

On the wiring layer 540, a planarizing film 550 is formed. On theplanarizing film 550, an infrared cut filter 560 is formed as a firstoptical filter layer. On the infrared cut filter 560, a color filter 580having spectral characteristics corresponding to each of the pixels 510is formed as a second optical filter layer. On the color filter 580, amicrolens 590 is formed. Note that a color filter is formed as the firstoptical filter layer in a case where the pixel 510 is constituted as aninfrared light pixel.

Furthermore, each of the pixels 510 has a separation wall 570 separatingthe first optical filter layer for each of the pixels. The separationwall 570 includes a metal film 570 a including W, Al, or the like, andan Si oxide film 570 b including SiO2, SiN, or the like. In the drawing,the separation walls 570 are formed in a lattice shape so as to beinterposed between the plurality of pixels 510 when the solid-stateimaging apparatus is viewed from the upper surface side.

In the front-illuminated solid-state imaging apparatus, as illustratedin FIG. 54, an intralayer lens 600 may be disposed between the wiringlayer 540 and the planarizing film 550.

(Structure Example of Back-Illuminated Solid-State Imaging Apparatus)

FIG. 55 is a cross-sectional view illustrating a structure example of aback-illuminated solid-state imaging apparatus.

As illustrated in FIG. 55, in the back-illuminated solid-state imagingapparatus, a PD 1019 formed for each of pixels 1010 receives incidentlight incident from a back (upper surface in the drawing) side of asemiconductor substrate 1018.

On the upper surface side of the semiconductor substrate 1018, aninsulating film 1015 such as a silicon oxide film is formed. On theinsulating film 1015, an infrared cut filter 1013 is formed as a firstoptical filter layer. On the infrared cut filter 1013, a color filter1012 having spectral characteristics corresponding to each of the pixels1010 is formed as a second optical filter layer. On the color filter1012, a microlens 1011 is formed. Note that a color filter is formed asthe first optical filter layer in a case where the pixel 1010 isconstituted as an infrared light pixel.

Furthermore, each of the pixels 1010 has a separation wall 1014separating the first optical filter layer for each of the pixels. Theseparation wall 1014 includes a metal film 1014 a including W, Al, orthe like, and an Si oxide film 1014 b including SiO2, SiN, or the like.In the drawing, the separation walls 1014 are formed in a lattice shapeso as to be interposed between the plurality of pixels 1010 when thesolid-state imaging apparatus is viewed from the upper surface side.

In the PD 1019, for example, an n-type semiconductor region 1020 isformed as a charge accumulation region for accumulating charges(electrons). In the PD 1019, the n-type semiconductor region 1020 isdisposed in p-type semiconductor regions 1016 and 1041 of thesemiconductor substrate 1018. The p-type semiconductor region 1041having a higher impurity concentration than the back (upper surface)side is disposed on a front (lower surface) side of the semiconductorsubstrate 1018 in the n-type semiconductor region 1020. That is, the PD1019 has a hole-accumulation diode (HAD) structure, and the p-typesemiconductor regions 1016 and 1041 are formed so as to suppressgeneration of a dark current at each interface between the upper surfaceside and the lower surface side of the n-type semiconductor region 1020.

In the semiconductor substrate 1018, a pixel separation unit 1030electrically separating the plurality of pixels 1010 from each other,and the PD 1019 is disposed in a region partitioned by the pixelseparation units 1030. In the drawing, the pixel separation units 1030are formed, for example, in a lattice shape so as to be interposedbetween the plurality of pixels 1010 when the solid-state imagingapparatus is viewed from the upper surface side, and the PD 1019 isformed in a region partitioned by the pixel separation units 1030.

In each of the PDs 1019, an anode is grounded. In the solid-stateimaging apparatus, a signal charge (for example, an electron)accumulated in the PD 1019 is read through a transfer transistor (MOSPET) (not illustrated) and the like, and output to a vertical signalline (VSL) (not illustrated) as an electric signal. Note that thetransistor is appropriately referred to as Tr in the followingdescription.

A wiring layer 1050 is disposed on a surface (lower surface) opposite tothe back surface (upper surface) of the semiconductor substrate 1018.

The wiring layer 1050 includes wiring 1051 and an insulating layer 1052and is formed such that the wiring 1051 is electrically connected toeach element in the insulating layer 1052. The wiring layer 1050 is aso-called multilayered wiring layer and formed by alternately laminatingan interlayer insulating film constituting the insulating layer 1052 andthe wiring 1051 a plurality of times.

A support substrate 1061 is disposed on a surface of the wiring layer1050 on the opposite side to the side on which the PD 1019 is disposed.For example, a substrate including a silicon semiconductor having athickness of several hundred μm is disposed as the support substrate1061.

The pixel separation unit 1030 includes a groove portion 1031, a fixedcharge film 1032, and an insulating film 1033.

The fixed charge film 1032 is formed so as to cover the groove portion1031 partitioning the plurality of pixels 1010 from each other on theback (upper surface) side of the semiconductor substrate 1018.

Specifically, the fixed charge film 1032 is disposed so as to cover aninner surface of the groove portion 1031 formed on the back (uppersurface) side of the semiconductor substrate 1018 with a fixedthickness. In addition, an insulating film 1033 is disposed (filled) soas to be embedded in the groove portion 1031 covered with the fixedcharge film 1032.

Here, the fixed charge film 1032 is formed using a high dielectricsubstance having a negative fixed charge such that a positive charge(hole) accumulation region is formed at an interface with thesemiconductor substrate 1018 to suppress generation of a dark current.Since the fixed charge film 1032 is formed so as to have a negativefixed charge, an electric field is applied to the interface with thesemiconductor substrate 1018 by the negative fixed charge, and apositive charge (hole) accumulation region is formed.

The fixed charge film 1032 can include, for example, a hafnium oxidefilm (HfO2 film). Furthermore, the fixed charge film 1032 can also beformed so as to include at least one of oxides of, for example, hafnium,zirconium, aluminum, tantalum, titanium, magnesium, yttrium, lanthanoidelements, and the like.

The present technology can be applied to the above-described solid-stateimaging apparatus.

(Configuration Example of Laminated Solid-State Imaging Apparatus)

FIG. 56 is a diagram illustrating an outline of a configuration exampleof a laminated solid-state imaging apparatus to which the presenttechnology can be applied.

A of FIG. 56 illustrates a schematic configuration example of anon-laminated solid-state imaging apparatus. As illustrated in A of FIG.56, a solid-state imaging apparatus 3010 includes one die (semiconductorsubstrate) 3011. On this die 3011, a pixel region 3012 in which pixelsare arranged in an array, a control circuit 3013 that performs drivingof a pixel and other various controls, and a logic circuit 3014 forsignal processing are mounted.

B and C of FIG. 56 illustrate schematic configuration examples of alaminated solid-state imaging apparatus. As illustrated in B and C ofFIG. 56, in a solid-state imaging apparatus 3020, two dies of a sensordie 3021 and a logic die 3024 are laminated and electrically connectedto each other to be constituted as a single semiconductor chip.

In B of FIG. 56, the pixel region 3012 and the control circuit 3013 aremounted on the sensor die 3021, and the logic circuit 3014 including asignal processing circuit that performs signal processing is mounted onthe logic die 3024.

In C of FIG. 56, the pixel region 3012 is mounted on the sensor die3021, and the control circuit 3013 and the logic circuit 3014 aremounted on the logic die 3024.

FIG. 57 is a cross-sectional view illustrating a first configurationexample of the laminated solid-state imaging apparatus 3020.

In the sensor die 3021, a photodiode (PD) constituting a pixel to be thepixel region 3012, a floating diffusion (FD), a Tr (MOS FET), a Tr to bethe control circuit 3013, and the like are formed. Moreover, in thesensor die 3021, a wiring layer 3101 having a multilayered wiring 3110,in this example, having three-layered wiring 3110, is formed. Note thatthe control circuit 3013 (Tr to be the control circuit 3013) can beconstituted not in the sensor die 3021 but in the logic die 3024.

In the logic die 3024, a Tr constituting the logic circuit 3014 isformed. Moreover, in the logic die 3024, a wiring layer 3161 having amultilayered wiring 3170, in this example, having three-layered wiring3170, is formed. Furthermore, a connection hole 3171 in which aninsulating film 3172 is formed on an inner wall surface is formed in thelogic die 3024, and a connection conductor 3173 to be connected to thewiring 3170 or the like is embedded in the connection hole 3171.

The sensor die 3021 and the logic die 3024 are bonded to each other suchthat the wiring layers 3101 and 3161 thereof face each other toconstitute a laminated solid-state imaging apparatus 3020 in which thesensor die 3021 and the logic die 3024 are laminated. On the surface towhich the sensor die 3021 and the logic die 3024 are bonded, a film 3191such as a protective film is formed.

In the sensor die 3021, a connection hole 3111 is formed which passesthrough the sensor die 3021 from the back side (side on which light isincident on PD) (upper side) of the sensor die 3021 and reaches thewiring 3170 as the uppermost layer of the logic die 3024. Moreover, inthe sensor die 3021, a connection hole 3121 reaching the wiring 3110 asthe first layer from the back side of the sensor die 3021 is formedclose to the connection hole 3111. An insulating film 3112 is formed onan inner wall surface of the connection hole 3111, and an insulatingfilm 3122 is formed on an inner wall surface of the connection hole3121. Then, connection conductors 3113 and 3123 are embedded in theconnection holes 3111 and 3121, respectively. The connection conductor3113 is electrically connected to the connection conductor 3123 on theback side of the sensor die 3021. As a result, the sensor die 3021 iselectrically connected to the logic die 3024 through the wiring layer3101, the connection hole 3121, the connection hole 3111, and the wiringlayer 3161.

FIG. 58 is a cross-sectional view illustrating a second configurationexample of the laminated solid-state imaging apparatus 3020.

In the second configuration example of the solid-state imaging apparatus3020, one connection hole 3211 formed in the sensor die 3021electrically connects the sensor die 3021 (wiring layer 3101 of thesensor die 3021 (wiring 3110 of the wiring layer 3101)) to the logic die3024 (wiring layer 3161 of the logic die 3024 (wiring 3170 of the wiringlayer 3161)).

In other words, in FIG. 58, the connection hole 3211 is formed so as topass through the sensor die 3021 from the back side of the sensor die3021, reach the wiring 3170 as the uppermost layer of the logic die3024, and reach the wiring 3110 as the uppermost layer of the sensor die3021. An insulating film 3212 is formed on an inner wall surface of theconnection hole 3211, and a connection conductor 3213 is embedded in theconnection hole 3211. In the example of FIG. 57 described above, thesensor die 3021 and the logic die 3024 are electrically connected toeach other by the two connection holes 3111 and 3121. However, in theexample of FIG. 58, the sensor die 3021 and the logic die 3024 areelectrically connected to each other by the one connection hole 3211.

FIG. 59 is a cross-sectional view illustrating a third configurationexample of the laminated solid-state imaging apparatus 3020.

The solid-state imaging apparatus 3020 of FIG. 59 is different from thecase of FIG. 57 in which the film 3191 such as a protective film isformed on the surface where the sensor die 3021 and the logic die 3024are bonded to each other in that the film 3191 such as a protective filmis not formed on the surface where the sensor die 3021 and the logic die3024 are bonded to each other.

The solid-state imaging apparatus 3020 of FIG. 59 is constituted byoverlapping the sensor die 3021 and the logic die 3024 with each othersuch that the wiring 3110 and the wiring 3170 are brought into directcontact with each other, and heating the sensor die 3021 and the logicdie 3024 while applying a required load to directly bond the wiring 3110and the wiring 3170 to each other.

FIG. 60 is a cross-sectional view illustrating another configurationexample of the laminated solid-state imaging apparatus to which thepresent technology can be applied.

In FIG. 60, a solid-state imaging apparatus 3401 has a three-layeredlaminated structure in which three dies of a sensor die 3411, a logicdie 3412, and a memory die 3413 are laminated.

The memory die 3413 includes, for example, a memory circuit that storesdata temporarily required in signal processing performed by the logicdie 3412.

In FIG. 60, the logic die 3412 and the memory die 3413 are laminated inthis order under the sensor die 3411. However, the logic die 3412 andthe memory die 3413 may be laminated in the reverse order, in otherwords, in the order of the memory die 3413 and the logic die 3412 underthe sensor die 3411.

Note that, in FIG. 60, in the sensor die 3411, a PD to be aphotoelectric conversion unit of a pixel and a source/drain region of apixel Tr are formed.

A gate electrode is formed around the PD via a gate insulating film, anda pixel Tr 3421 and a pixel Tr 3422 are formed by the gate electrode anda pair of source/drain regions.

The pixel Tr 3421 adjacent to the PD is a transfer Tr, and one of thepair of source/drain regions forming the pixel Tr 3421 is an FD.

Furthermore, an interlayer insulating film is formed in the sensor die3411, and a connection hole is formed in the interlayer insulating film.A connection conductor 3431 connected to the pixel Tr 3421 and the pixelTr 3422 is formed in the connection hole.

Moreover, a wiring layer 3433 having multilayered wiring 3432 connectedto the connection conductors 3431 is formed in the sensor die 3411.

Furthermore, an aluminum pad 3434 to be an electrode for externalconnection is formed in the lowermost layer of the wiring layer 3433 ofthe sensor die 3411. In other words, the aluminum pad 3434 is formed ata position closer to a bonding surface 3440 to the logic die 3412 thanthe wiring 3432 in the sensor die 3411. The aluminum pad 3434 is used asone end of wiring relating to input and output of a signal with theoutside.

Moreover, a contact 3441 used for electrical connection with the logicdie 3412 is formed in the sensor die 3411. The contact 3441 is connectedto a contact 3451 of the logic die 3412 and also to an aluminum pad 3442of the sensor die 3411.

In addition, a pad hole 3443 is formed so as to reach the aluminum pad3442 from the back side (upper side) of the sensor die 3411 in thesensor die 3411.

The present technology can also be applied to the above-describedsolid-state imaging apparatus. Note that only one color filter (CF) isillustrated as an optical filter layer in FIGS. 57 to 60, but actually,a first optical filter layer and a second optical filter layer disposedon the first optical filter layer are formed.

(Configuration Example of Solid-State Imaging Apparatus Sharing aPlurality of Pixels)

FIG. 61 is a plan view illustrating a first configuration example of asolid-state imaging apparatus sharing a plurality of pixels to which thepresent technology can be applied. FIG. 62 is a cross-sectional viewtaken along line A-A of FIG. 61.

A solid-state imaging apparatus 4010 has a pixel region 4011 in whichpixels are arranged in a two-dimensional array. The pixel region 4011 isconstituted by using a total of four pixels of horizontal 2pixels×vertical 2 pixels as a shared pixel unit 4012 sharing a pixel Tr(MOS FET) and the like, and arranging the shared pixel units 4012 in atwo-dimensional array.

The four pixels of the shared pixel unit 4012 sharing four pixels ofhorizontal 2 pixels×vertical 2 pixels include photodiodes (PDs) 40211,40212, 40213, and 40214, respectively, and share one floating diffusion(FD) 4030. Furthermore, the shared pixel unit 4012 includes a transferTr 4041 i for the PD 4021 i (here, 1, 2, 3, or 4), and a reset Tr 4051,an amplification Tr 4052, and a selection Tr 4053 as shared Trs sharedby the four pixels.

The FD 4030 is disposed at the center surrounded by the four PDs 40211to 40214. The FD 4030 is connected to a source/drain region S/D as adrain of the reset Tr 4051 and a gate G of the amplification Tr 4052 viawiring 4071. The transfer Tr 4041 i includes a gate 4042 i disposedbetween the PD 40211 for the transfer Tr 40411 and the FD 4030 close tothe PD 40211, and operates according to a voltage applied to the gate4042 i.

Here, a region including the PDs 40211 to 40214, the FD 4030, and thetransfer Trs 40411 to 40414 of the shared pixel unit 4012 in each row isreferred to as a PD forming region 4061. Furthermore, among the pixelsTrs of the shared pixel unit 4012 in each row, a region including thereset Tr 4051, the amplification Tr 4052, and the selection Tr 4053shared by the four pixels is referred to as a Tr forming region 4062.The Tr forming region 4062 and the PD forming region 4061 continuous ina horizontal direction are alternately disposed in a vertical directionof the pixel region 4011.

Each of the reset Tr 4051, the amplification Tr 4052, and the selectionTr 4053 is constituted by a pair of source/drain regions S/D and a gateG. One of the pair of source/drain regions S/D functions as a source,and the other functions as a drain.

For example, as illustrated in the cross-sectional view of FIG. 62, thePDs 40211 to 40214, the FD 4030, the transfer Trs 40411 to 40414, thereset Tr 4051, the amplification Tr 4052, and the selection Tr 4053 areformed in a p-type semiconductor region (p-well) 4210 formed in ann-type semiconductor substrate 4200.

As illustrated in FIG. 61, a pixel separation unit 4101 is formed in thePD forming region 4061, and an element separation unit 4102 is formed inthe Tr forming region 4062 (region including the Tr forming region4062). For example, as illustrated in FIG. 62, the element separationunit 4102 includes a p-type semiconductor region 4211 disposed in ap-type semiconductor region 4210 and an insulating film (for example,silicon oxide Film) 4212 disposed on a surface of the p-typesemiconductor region 4211. The pixel separation unit 4101 (notillustrated) can be constituted similarly.

A well contact 4111 for applying a fixed voltage to the p-typesemiconductor region 4210 is formed in the pixel region 4011. The wellcontact 4111 can be constituted as a p-type semiconductor region whichis an impurity diffusion region disposed on a surface of the p-typesemiconductor region 4231 disposed in the p-type semiconductor region4210. The well contact 4111 is a p-type semiconductor region having ahigher impurity concentration than the p-type semiconductor region 4231.The well contact 4111 (and the lower p-type semiconductor region 4231)also serves as the element separation unit 4102, and is formed betweenthe shared Trs (reset Tr 4051, amplification Tr 4052, and selection Tr4053) of the shared pixel unit 4012 horizontally adjacent to each other.The well contact 4111 is connected to required wiring 4242 of a wiringlayer 4240 via a conductive via 4241. A required fixed voltage isapplied from the wiring 4242 to the p-type semiconductor region 4210through the conductive via 4241 and the well contact 4111. The wiringlayer 4240 is formed by disposing multilayered wiring 4242 via aninsulating film 4243. On the wiring layer 4240, a color filter (CF) anda microlens (not illustrated) are formed via a planarizing film.

FIG. 63 is a diagram illustrating an example of an equivalent circuit ofthe shared pixel unit 4012 sharing four pixels. In the equivalentcircuit of the shared pixel unit 4012 sharing four pixels, the four PDs40211 to 40214 are connected to sources of the corresponding fourtransfer Trs 40411 to 40414, respectively. A drain of each transfer Tr4041 i is connected to a source of the reset Tr 4051. A drain of eachtransfer Tr 4041 i is the common FD 4030. The FD 4030 is connected to agate of the amplification Tr 4052. A source of the amplification Tr 4052is connected to a drain of the selection Tr 4053. A drain of the resetTr 4051 and a drain of the amplification Tr 4052 are connected to apower supply VDD. A source of the selection Tr 4053 is connected to avertical signal line (VSL).

FIG. 64 is a plan view illustrating a second configuration example ofthe solid-state imaging apparatus sharing a plurality of pixels to whichthe present technology can be applied.

A solid-state imaging apparatus 4400 has a pixel region 4401 in whichpixels are arranged in a two-dimensional array. The pixel region 4401 isconstituted by using a total of eight pixels of horizontal 2pixels×vertical 4 pixels as a shared pixel unit 4410, and arranging theshared pixel units 4410 in a two-dimensional array.

The shared pixel unit 4410 sharing eight pixels of horizontal 2pixels×vertical 4 pixels includes a first light receiving unit 4421 anda second light receiving unit 4422. The first light receiving unit 4421and the second light receiving unit 4422 are arranged in a longitudinaldirection (y direction) in the shared pixel unit 4410.

The first light receiving unit 4421 includes PDs 44411, 44412, 44413,and 44414 arranged in horizontal 2 pixels×vertical 2 pixels, fourtransfer Trs 4451 corresponding to the PDs 44411 to 44414, respectively,and an FD 4452 shared by the PDs 44411 to 44414. The FD 4452 is disposedat the center of the PDs 44411 to 44414.

The second light receiving unit 4422 includes PDs 44415, 44416, 44417,and 44418 arranged in horizontal 2 pixels×vertical 2 pixels, fourtransfer Trs 4461 corresponding to the PDs 44415 to 44418, respectively,and an FD 4462 shared by the PDs 44415 to 44418. The FD 4462 is disposedat the center of the PDs 44415 to 44418.

The transfer Tr 4451 includes a gate 4451G disposed between the PD 44411for the transfer Tr 4451 and the FD 4452, and operates according to avoltage applied to the gate 4451G. Similarly, the transfer Tr 4461includes a gate 4461G disposed between the PD 4441 i for the transfer Tr4461 and the FD 4462, and operates according to a voltage applied to thegate 4461G.

Furthermore, the shared pixel unit 4410 includes a first Tr group 4423and a second Tr group 4424. In the first Tr group 4423 and the second Trgroup 4424, a reset Tr 4452, an amplification Tr 4453, and a selectionTr 4454 shared by eight pixels of the shared pixel unit 4410 areseparately disposed. In FIG. 64, the amplification Tr 4453 and theselection Tr 4454 are disposed in the first Tr group 4423, and the resetTr 4452 is disposed in the second Tr group 4424.

The first Tr group 4423 is disposed between the first light receivingunit 4421 and the second light receiving unit 4422. The second Tr group4424 is disposed in a region of the second light receiving unit 4422 onthe side opposite to the disposition side of the first Tr group 4423 ina peripheral region of the second light receiving unit 4422.

Note that the first light receiving unit 4421 and the second lightreceiving unit 4422 are formed in a lateral direction (x direction).

Furthermore, each of the reset Tr 4452, the amplification Tr 4453, andthe selection Tr 4454 is constituted by a pair of source/drain regionsS/D and a gate G. One of the pair of source/drain regions S/D functionsas a source, and the other functions as a drain.

The pair of source/drain regions S/D and the gate G constituting thereset Tr 4452, the amplification Tr 4453, and the selection Tr 4454 aredisposed in a lateral direction (x direction). The gate G constitutingthe reset Tr 4452 is disposed in a region substantially facing the lowerright PD 44418 of the second light receiving unit 4422 in a longitudinaldirection (y direction).

A first well contact 4431 and a second well contact 4432 are disposedbetween the two shared pixel units 4410 horizontally adjacent to eachother. The first light receiving unit 4421, the second light receivingunit 4422, the first Tr group 4423, and the second Tr group 4424 areformed in a semiconductor region as a predetermined well region formedin a Si substrate. The first well contact 4431 and the second wellcontact 4432 are contacts electrically connecting a predetermined wellregion to internal wiring of the solid-state imaging apparatus 4400. Thefirst well contact 4431 is disposed between the first Tr groups 4423 ofthe two shared pixel units 4410 horizontally adjacent to each other. Thesecond well contact 4432 is disposed between the second Tr groups 4424of the two shared pixel units 4410 horizontally adjacent to each other.

Furthermore, parts in the shared pixel unit 4410 are electricallyconnected to each other so as to satisfy a connection relationshipaccording to the equivalent circuit sharing four pixels illustrated inFIG. 63.

The present technology can also be applied to the above-describedsolid-state imaging apparatus.

Note that the present technology is not limited to application to asolid-state imaging apparatus, but can also be applied to an imagingapparatus. Here, the imaging apparatus refers to a camera system such asa digital still camera or a digital video camera, or an electronicdevice having an imaging function, such as a mobile phone. Note thatthere is a case where a module form mounted on an electronic device,that is, a camera module is used as an imaging apparatus.

6. Configuration Example of Electronic Device

Here, a configuration example of the electronic device to which thepresent technology is applied will be described with reference to FIG.65.

An electronic device 5001 illustrated in FIG. 65 includes an opticallens 5011, a shutter apparatus 5012, an image sensor 5013, a drivingcircuit 5014, and a signal processing circuit 5015. FIG. 65 illustratesan embodiment in a case where the above-described solid-state imagingapparatus 31 of the present technology is disposed in an electronicdevice (digital still camera) as the image sensor 5013.

The optical lens 5011 forms an image of image light (incident light)from a subject on an imaging surface of the image sensor 5013. As aresult, a signal charge is accumulated in the image sensor 5013 for acertain period of time. The shutter apparatus 5012 controls a lightirradiation period and a light-shielding period for the image sensor5013.

The driving circuit 5014 supplies a driving signal to the shutterapparatus 5012 and the image sensor 5013. A driving signal supplied tothe shutter apparatus 5012 is a signal for controlling shutter operationof the shutter apparatus 5012. A driving signal supplied to the imagesensor 5013 is a signal for controlling signal transfer operation of theimage sensor 5013. The image sensor 5013 transfers a signal by a drivingsignal (timing signal) supplied from the driving circuit 5014. Thesignal processing circuit 5015 performs various types of signalprocessing on a signal output from the image sensor 5013. A video signalwhich has been subjected to signal processing is stored in a storagemedium such as a memory or is output to a monitor.

The electronic device 5001 of the present embodiment can suppress colorseparation and deterioration of S/N in the image sensor 5013, and as aresult, can provide an electronic device capable of obtaining ahigh-quality image.

7. Use Example of Image Sensor

Finally, a use example of an image sensor to which the presenttechnology is applied will be described.

FIG. 66 is a diagram illustrating a use example of the above-describedimage sensor.

The above-described image sensor can be used, for example, in variouscases of sensing light such as visible light, infrared light,ultraviolet light, or an X-ray as described below.

-   -   An apparatus for imaging an image used for appreciation, such as        a digital camera or a portable device with a camera function    -   An apparatus used for transportation, such as a vehicle-mounted        sensor for imaging the front, the back, the surrounding, the        inside, or the like of an automobile for safe driving such as        automatic stop, for recognition of a driver's condition, and the        like, a surveillance camera for monitoring a running vehicle and        a road, or a measuring sensor for measuring a distance between        vehicles or the like    -   An apparatus used for home electronics, such as a television        set, a refrigerator, or an air conditioner for imaging a gesture        of a user and operating a device according to the gesture    -   An apparatus used for medical care and health care, such as an        endoscope or an apparatus for receiving infrared light for        angiography    -   An apparatus used for security, such as a surveillance camera        for crime prevention or a camera for personal authentication    -   An apparatus used for beauty care, such as a skin measurement        device for imaging a skin or a microscope for imaging a scalp    -   An apparatus used for sports, such as an action camera or a        wearable camera for sports and the like    -   An apparatus used for agriculture, such as a camera for        monitoring a condition of a field and a crop

8. Application Example to Endoscopic Surgery System

The technology according to the present disclosure (the presenttechnology) can be applied to various products. For example, thetechnology according to the present disclosure may be applied to anendoscopic surgical system.

FIG. 67 is a diagram illustrating an example of a schematicconfiguration of an endoscopic surgical system to which the technologyaccording to the present disclosure (the present technology) can beapplied.

FIG. 67 illustrates a situation in which a surgeon (physician) 11131 isperforming surgery on a patient 11132 on a patient bed 11133 using anendoscopic surgical system 11000. As illustrated in the drawing, theendoscopic surgical system 11000 includes an endoscope 11100, anothersurgical tool 11110 such as a pneumoperitoneum tube 11111 or an energytreatment tool 11112, a support arm device 11120 for supporting theendoscope 11100, and a cart 11200 on which various devices forendoscopic surgery are mounted.

The endoscope 11100 includes a lens barrel 11101 to be inserted into abody cavity of the patient 11132 in a region of a predetermined lengthfrom a tip thereof, and a camera head 11102 connected to a proximal endof the lens barrel 11101. In the illustrated example, the endoscope11100 configured as a so-called rigid mirror including the rigid lensbarrel 11101 is illustrated, but the endoscope 11100 may be configuredas a so-called flexible mirror including a flexible lens barrel.

At the tip of the lens barrel 11101, an opening into which an objectivelens is fitted is disposed. A light source device 11203 is connected tothe endoscope 11100. Light generated by the light source device 11203 isguided to the tip of the lens barrel by a light guide extended insidethe lens barrel 11101, and is emitted toward an observation target in abody cavity of the Patient 11132 via the objective lens. Note that theendoscope 11100 may be a direct view mirror, a perspective view mirror,or a side view mirror.

An optical system and an imaging element are disposed inside the camerahead 11102. Reflected light (observation light) from an observationtarget is converged on the imaging element by the optical system. Theobservation light is photoelectrically converted by the imaging element,and an electric signal corresponding to the observation light, that is,an image signal corresponding to an observation image is generated. Theimage signal is transmitted as RAW data to a camera control unit (CCU)11201.

The CCU 11201 includes a central processing unit (CPU), a graphicsprocessing unit (GPU), and the like, and integrally controls operationsof the endoscope 11100 and the display device 11202. Moreover, the CCU11201 receives an image signal from the camera head 11102, and performs,on the image signal, various image processing for displaying an imagebased on the image signal, such as development processing (demosaicprocessing), for example.

The display device 11202 displays an image based on an image signalsubjected to image processing by the CCU 11201 under the control of theCCU 11201.

The light source device 11203 includes a light source such as a lightemitting diode (LED), for example, and supplies irradiation light forimaging a surgical site or the like to the endoscope 11100.

An input device 11204 is an input interface to the endoscopic surgicalsystem 11000. A user can input various kinds of information andinstructions to the endoscopic surgical system 11000 via the inputdevice 11204. For example, the user inputs an instruction or the like tochange imaging conditions (type of irradiation light, magnification,focal length, and the like) by the endoscope 11100.

A treatment tool control device 11205 controls driving of the energytreatment tool 11112 for cauterizing and cutting a tissue, sealing ablood vessel, or the like. A pneumoperitoneum device 11206 feeds a gasinto a body cavity via the pneumoperitoneum tube 11111 in order toinflate the body cavity of the patient 11132 for the purpose of securinga field of view by the endoscope 11100 and securing a working space of asurgeon. A recorder 11207 is a device capable of recording various kindsof information regarding surgery. A printer 11208 is a device capable ofprinting various kinds of information regarding surgery in variousformats such as a text, an image, and a graph.

Note that the light source device 11203 for supplying irradiation lightused for imaging a surgical site to the endoscope 11100 may include anLED, a laser light source, or a white light source constituted by acombination thereof, for example. In a case where the white light sourceis constituted by a combination of RGB laser light sources, the outputintensity and the output timing of each color (each wavelength) can becontrolled with high precision, and therefore adjustment of a whitebalance of an imaged image can be performed by the light source device11203. Furthermore, in this case, by irradiating an observation targetwith laser light from each of the RGB laser light sources in a timedivision manner and controlling driving of an imaging element of thecamera head 11102 in synchronization with the irradiation timing, it isalso possible to image an image corresponding to each of RGB in a timedivision manner. According to this method, a color image can be obtainedwithout disposing a color filter in the imaging element.

Furthermore, driving of the light source device 11203 may be controlledso as to change the intensity of light output at predetermined timeintervals. By controlling driving of the imaging element of the camerahead 11102 in synchronization with the timing of the change of theintensity of the light to acquire an image in a time division manner andsynthesizing the image, a high dynamic range image without so-calledblocked up shadows or blown out highlights can be generated.

Furthermore, the light source device 11203 may be configured so as to beable to supply light in a predetermined wavelength band corresponding tospecial light observation. In the special light observation, forexample, by irradiation with light in a narrower band than irradiationlight (in other words, white light) at the time of ordinary observationusing wavelength dependency of light absorption in a body tissue, apredetermined tissue such as a blood vessel of a mucosal surface layeris imaged at a high contrast, that is, so-called narrow band imaging isperformed. Alternatively, in the special light observation, fluorescenceobservation for obtaining an image by fluorescence generated byirradiation with excitation light may be performed. In the fluorescenceobservation, it is possible to observe fluorescence from a body tissue(autofluorescence observation) by irradiating the body tissue withexcitation light, or to obtain a fluorescent image by injecting areagent such as indocyanine green (ICG) into a body tissue andirradiating the body tissue with excitation light corresponding to afluorescence wavelength of the reagent, for example. The light sourcedevice 11203 can be configured so as to be able to supply narrow bandlight and/or excitation light corresponding to such special lightobservation.

FIG. 68 is a block diagram illustrating examples of functionalconfigurations of the camera head 11102 and the CCU 11201 illustrated inFIG. 67.

The camera head 11102 includes a lens unit 11401, an imaging unit 11402,a driving unit 11403, a communication unit 11404, and a camera headcontrol unit 11405. The CCU 11201 includes a communication unit 11411,an image processing unit 11412, and a 11413. The camera head 11102 andthe CCU 11201 are communicably connected to each other by a transmissioncable 11400.

The lens unit 11401 is an optical system disposed at a connectingportion with the lens barrel 11101. Observation light taken in from atip of the lens barrel 11101 is guided to the camera head 11102 and isincident on the lens unit 11401. The lens unit 11401 includes acombination of a plurality of lenses including a zoom lens and a focuslens.

The imaging unit 11402 includes an imaging element. The imaging unit11402 may include one imaging element (so-called single plate type) or aplurality of imaging elements (so-called multiplate type). In a casewhere the imaging unit 11402 includes multiplate type imaging elements,for example, an image signal corresponding to each of RGB may begenerated by each imaging element, and a color image may be obtained bysynthesizing these image signals. Alternatively, the imaging unit 11402may include a pair of imaging elements for acquiring an image signal foreach of the right eye and the left eye corresponding tothree-dimensional (3D) display. By performing the 3D display, thesurgeon 11131 can grasp the depth of a living tissue in a surgical sitemore accurately. Incidentally, in a case where the imaging unit 11402includes multiplate type imaging elements, a plurality of lens units11401 can be disposed corresponding to the respective imaging elements.

Furthermore, the imaging unit 11402 is not necessarily disposed in thecamera head 11102. For example, the imaging unit 11402 may be disposedjust behind an objective lens inside the lens barrel 11101.

The driving unit 11403 includes an actuator, and moves a zoom lens and afocus lens of the lens unit 11401 by a predetermined distance along anoptical axis under control of the camera head control unit 11405. As aresult, the magnification and the focus of an image imaged by theimaging unit 11402 can be appropriately adjusted.

The communication unit 11404 includes a communication device fortransmitting and receiving various kinds of information to and from theCCU 11201. The communication unit 11404 transmits an image signalobtained from the imaging unit 11402 as RAW data to the CCU 11201 viathe transmission cable 11400.

Furthermore, the communication unit 11404 receives a control signal forcontrolling driving of the camera head 11102 from the CCU 11201, andsupplies the control signal to the camera head control unit 11405. Thecontrol signal includes information regarding imaging conditions such asinformation indicating designation of a frame rate of an imaged image,information indicating designation of an exposure value at the time ofimaging, and/or information indicating designation of the magnificationand the focus of an imaged image, for example.

Note that the imaging conditions such as the frame rate, the exposurevalue, the magnification, and the focus may be appropriately designatedby a user, or may be automatically set by the control unit 11413 of theCCU 11201 on the basis of an acquired image signal. In the latter case,the endoscope 11100 has a so-called auto exposure (AR) function, aso-called auto focus (AF) function, and a so-called auto white balance(AWB) function.

The camera head control unit 11405 controls driving of the camera head11102 on the basis of a control signal from the CCU 11201 received viathe communication unit 11404.

The communication unit 11411 includes a communication device fortransmitting and receiving various kinds of information to and from thecamera head 11102. The communication unit 11411 receives an image signaltransmitted from the camera head 11102 via the transmission cable 11400.

Furthermore, the communication unit 11411 transmits a control signal forcontrolling driving of the camera head 11102 to the camera head 11102.The image signal and the control signal can be transmitted by electriccommunication, optical communication, or the like.

The image processing unit 11412 performs various kinds of imageprocessing on the image signal which is RAW data transmitted from thecamera head 11102.

The control unit 11413 performs various kinds of control concerningimaging of a surgical site or the like by the endoscope 11100 anddisplay of an imaged image obtained by imaging a surgical site or thelike. For example, the control unit 11413 generates a control signal forcontrolling driving of the camera head 11102.

Furthermore, the control unit 11413 causes the display device 11202 todisplay an imaged image of a surgical site or the like on the basis ofan image signal subjected to image processing by the image processingunit 11412. In this case, the control unit 11413 may recognize variousobjects in the imaged image using various image recognition techniques.For example, by detecting the shape, color, and the like of an edge ofan object included in the imaged image, the control unit 11413 canrecognize a surgical tool such as forceps, a specific living body part,bleeding, a mist at the time of using the energy treatment tool 11112,and the like. When the display device 11202 displays the imaged image,the control unit 11413 may cause the display device 11202 to superimposeand display various kinds of surgical support information on the imageof the surgical site using the recognition result. The surgical supportinformation is superimposed and displayed, and presented to the surgeon11131. This makes it possible to reduce a burden on the surgeon 11131and makes it possible for the surgeon 11131 to reliably perform surgery.

The transmission cable 11400 connecting the camera head 11102 to the CCU11201 is an electric signal cable corresponding to communication of anelectric signal, an optical fiber corresponding to opticalcommunication, or a composite cable thereof.

Here, in the illustrated example, communication is performed by wireusing the transmission cable 11400, but communication between the camerahead 11102 and the CCU 11201 may be performed wirelessly.

An example of the endoscopic surgical system to which the technologyaccording to the present disclosure can be applied has been describedabove. The technology according to the present disclosure can be appliedto the imaging unit 11402 of the camera head 11102 among theabove-described configurations. Specifically, the solid-state imagingapparatus 31 of FIG. 3 can be applied to the imaging unit 10402.Application of the technology according to the present disclosure to theimaging unit 11402 makes it possible to suppress occurrence of colormixing between visible light pixels and between a visible light pixeland an infrared light pixel, and to suppress color separation anddeterioration of S/N. Therefore, for example, in an endoscopicexamination, even in a case where an observation image of visible lightand an observation image of infrared light are imaged at the same time,a clearer surgical site image can be obtained. Therefore, a surgeon canconfirm the surgical site reliably.

Note that the endoscopic surgical system has been described as anexample here. However, the technology according to the presentdisclosure may also be applied to, for example, a microscopic surgerysystem or the like.

9. Application Example to Mobile Body

Moreover, the technology according to the present disclosure (thepresent technology) can be applied to various products. For example, thetechnology according to the present disclosure may be achieved as anapparatus mounted on any type of mobile body such as an automobile, anelectric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, apersonal mobility, an airplane, a drone, a ship, or a robot.

FIG. 69 is a block diagram illustrating an example of a schematicconfiguration of a vehicle control system which is an example of amobile body control system to which the technology according to thepresent disclosure can be applied.

A vehicle control system 12000 includes a plurality of electroniccontrol units connected to one another via a communication network12001. In the example illustrated in FIG. 69, the vehicle control system12000 includes a drive system control unit 12010, a body system controlunit 12020, a vehicle external information detection unit 12030, avehicle internal information detection unit 12040, and an integratedcontrol unit 12050. Furthermore, as a functional configuration of theintegrated control unit 12050, a microcomputer 12051, an audio imageoutput unit 12052, and an on-vehicle network interface (I/F) 12053 areillustrated.

The drive system control unit 12010 controls an operation of a devicerelated to a drive system of a vehicle according to various programs.For example, the drive system control unit 12010 functions as a controldevice of a driving force generating device for generating a drivingforce of a vehicle such as an internal combustion engine or a drivingmotor, a driving force transmitting mechanism for transmitting a drivingforce to wheels, a steering mechanism for adjusting a rudder angle of avehicle, a braking device for generating a braking force of a vehicle,or the like.

The body system control unit 12020 controls operations of variousdevices mounted on a vehicle body according to various programs. Forexample, the body system control unit 12020 functions as a controldevice of a keyless entry system, a smart key system, a power windowdevice, or various lamps such as a head lamp, a back lamp, a brake lamp,a turn indicator, and a fog lamp. In this case, to the body systemcontrol unit 12020, a radio wave transmitted from a portable devicesubstituted for a key or signals of various switches can be input. Thebody system control unit 12020 receives input of the radio wave orsignals and controls a door lock device, a power window device, a lamp,and the like of a vehicle.

The vehicle external information detection unit 12030 detectsinformation outside a vehicle on which the vehicle control system 12000is mounted. For example, to the vehicle external information detectionunit 12030, an imaging unit 12031 is connected. The vehicle externalinformation detection unit 12030 causes the imaging unit 12031 to imagean image outside a vehicle and receives an imaged image. The vehicleexternal information detection unit 12030 may perform object detectionprocessing or distance detection processing of a person, a car, anobstacle, a sign, a character on a road surface, or the like on thebasis of the received image.

The imaging unit 12031 is a light sensor for receiving light andoutputting an electric signal corresponding to the amount of lightreceived. The imaging unit 12031 can output an electric signal as animage or output the electric signal as distance measurement information.Furthermore, the light received by the imaging unit 12031 may be visiblelight or invisible light such as infrared light.

The vehicle internal information detection unit 12040 detectsinformation inside a vehicle. To the vehicle internal informationdetection unit 12040, for example, a driver state detection unit 12041for detecting the state of a driver is connected. The driver statedetection unit 12041 includes, for example, a camera for imaging adriver. The vehicle internal information detection unit 12040 maycalculate the degree of fatigue or the degree of concentration of adriver or may determine whether the driver is dozing off on the basis ofdetection information input from the driver state detection unit 12041.

The microcomputer 12051 can calculate a control target value of adriving force generating device, a steering mechanism, or a brakingdevice on the basis of information inside and outside a vehicle,acquired by the vehicle external information detection unit 12030 or thevehicle internal information detection unit 12040, and can output acontrol command to the drive system control unit 12010. For example, themicrocomputer 12051 can perform cooperative control aiming at realizinga function of advanced driver assistance system (ADAS) includingcollision avoidance or impact mitigation of a vehicle, following travelbased on inter-vehicle distance, vehicle speed maintenance travel,vehicle collision warning, vehicle lane departure warning, and the like.

Furthermore, the microcomputer 12051 can perform cooperative controlaiming at, for example, automatic driving that autonomously travelswithout depending on driver's operation by controlling a driving forcegenerating device, a steering mechanism, a braking device, or the likeon the basis of information around a vehicle, acquired by the vehicleexternal information detection unit 12030 or the vehicle internalinformation detection unit 12040.

Furthermore, the microcomputer 12051 can output a control command to thebody system control unit 12020 on the basis of vehicle externalinformation acquired by the vehicle external information detection unit12030. For example, the microcomputer 12051 can perform cooperativecontrol aiming at antiglare such as switching from high beam to low beamby controlling a headlamp according to the position of a precedingvehicle or an oncoming vehicle detected by the vehicle externalinformation detection unit 12030.

The audio image output unit 12052 transmits at least one of an audiooutput signal or an image output signal to an output device capable ofvisually or audibly notifying a passenger of a vehicle or the outside ofthe vehicle of information. In the example of FIG. 69, as the outputdevice, an audio speaker 12061, a display unit 12062, and an instrumentpanel 12063 are illustrated. The display unit 12062 may include anon-board display and/or a head-up display, for example.

FIG. 70 is a diagram illustrating an example of an installation positionof the imaging unit 12031.

In FIG. 70, the vehicle 12100 includes imaging units 12101, 12102,12103, 12104, and 12105 as the imaging unit 12031.

The imaging units 12101, 12102, 12103, 12104, and 12105 are disposed,for example, in a front nose, a side mirror, a rear bumper, and a backdoor of the vehicle 12100, in an upper portion of a front glass in apassenger compartment, and the like. The imaging unit 12101 disposed ina front nose and the imaging unit 12105 disposed in an upper portion ofa front glass in a passenger compartment mainly acquire images in frontof the vehicle 12100. The imaging units 12102 and 12103 disposed in sidemirrors mainly acquire images on sides of the vehicle 12100. The imagingunit 12104 disposed in a rear bumper or a back door mainly acquires animage behind the vehicle 12100. The front images acquired by the imagingunits 12101 and 12105 are mainly used for detecting a preceding vehicle,a pedestrian, an obstacle, a traffic signal, a traffic sign, a lane, orthe like.

Note that FIG. 70 illustrates examples of imaging ranges of the imagingunits 12101 to 12104. An imaging range 12111 indicates an imaging rangeof the imaging unit 12101 disposed in a front nose. Imaging ranges 12112and 12113 indicate imaging ranges of the imaging units 12102 and 12103disposed in side mirrors, respectively. An imaging range 12114 indicatesan imaging range of the imaging unit 12104 disposed in a rear bumper ora back door. For example, by superimposing image data imaged by theimaging units 12101 to 12104 on one another, an overhead view image ofthe vehicle 12100 viewed from above is obtained.

At least one of the imaging units 12101 to 12104 may have a function ofacquiring distance information. For example, at least one of the imagingunits 12101 to 12104 may be a stereo camera including a plurality ofimaging elements, or may be an imaging element having pixels for phasedifference detection.

For example, the microcomputer 12051 determines a distance to eachthree-dimensional object in the imaging range 12111 to 12114 and atemporal change (relative speed with respect to the vehicle 12100) ofthe distance on the basis of the distance information obtained from theimaging units 12101 to 12104, and can thereby particularly extract athree-dimensional object which is the nearest three-dimensional objecton a traveling path of the vehicle 12100 and is traveling at apredetermined speed (for example, 0 km/h or more) in substantially thesame direction as the vehicle 12100 as a preceding vehicle. Moreover,the microcomputer 12051 can set an inter-vehicle distance to be securedin advance in front of the preceding vehicle, and can perform automaticbrake control (including following stop control), automatic accelerationcontrol (including following start control), and the like. In this way,it is possible to perform cooperative control aiming at, for example,automatic driving that autonomously travels without depending ondriver's operation.

For example, the microcomputer 12051 classifies three-dimensional objectdata related to a three-dimensional object into a two-wheeled vehicle, aregular vehicle, a large vehicle, a pedestrian, and anotherthree-dimensional object such as a telegraph pole on the basis of thedistance information obtained from the imaging units 12101 to 12104 andextracts data, and can use the extracted data for automatic avoidance ofan obstacle. For example, the microcomputer 12051 identifies an obstaclearound the vehicle 12100 as an obstacle that a driver of the vehicle12100 can see and an obstacle that is difficult to see. Then, themicrocomputer 12051 judges a collision risk indicating a risk ofcollision with each obstacle. When the collision risk is higher than aset value and there is a possibility of collision, the microcomputer12051 can perform driving assistance for avoiding collision byoutputting an alarm to a driver via the audio speaker 12061 or thedisplay unit 12062, or performing forced deceleration or avoidingsteering via the drive system control unit 12010.

At least one of the imaging units 12101 to 12104 may be an infraredcamera for detecting an infrared ray. For example, the microcomputer12051 can recognize a pedestrian by determining whether or not apedestrian exists in imaged images of the imaging units 12101 to 12104.Such recognition of a pedestrian is performed by, for example, aprocedure of extracting characteristic points in imaged images of theimaging units 12101 to 12104 as infrared cameras and a procedure ofperforming pattern matching processing on a series of characteristicpoints indicating an outline of an object and determining whether or nota pedestrian exists. If the microcomputer 12051 determines that apedestrian exists in imaged images of the imaging units 12101 to 12104and recognizes a pedestrian, the audio image output unit 12052 controlsthe display unit 12062 such that the display unit 12062 superimposes anddisplays a rectangular contour line for emphasis on the recognizedpedestrian. Furthermore, the audio image output unit 12052 may controlthe display unit 12062 such that the display unit 12062 displays an iconor the like indicating a pedestrian at a desired position.

An example of the vehicle control system to which the technologyaccording to the present disclosure can be applied has been describedabove. The technology according to the present disclosure can be appliedto the imaging unit 12031 (at least one of the imaging units 12101 to12104) among the above-described configurations. Specifically, thesolid-state imaging apparatus 31 of FIG. 3 can be applied to the imagingunit 12031. Application of the technology according to the presentdisclosure to the imaging unit 12031 makes it possible to suppressoccurrence of color mixing between visible light pixels and between avisible light pixel and an infrared light pixel, and to suppress colorseparation and deterioration of S/N. Therefore, even if the imaging unit12031 has a function of acquiring distance information, a more easilyviewable imaged image can be obtained. Therefore, fatigue of a drivercan be reduced.

Note that embodiments of the present technology are not limited to theabove-described embodiments, and various modifications can be made tothem without departing from the scope of the present technology.

Moreover, the present technology can have the following configurations.

(1)

A solid-state imaging apparatus including a plurality of pixels arrangedin a pixel region, in which

-   -   each of the pixels has:    -   a first optical filter layer disposed on a photoelectric        conversion unit;

a second optical filter layer disposed on the first optical filterlayer; and

a separation wall separating at least a part of the first optical filterlayer for each of the pixels, and

-   -   either the first optical filter layer or the second optical        filter layer in at least one of the pixels is formed by an        infrared cut filter, while the other is formed by a color        filter.

(2)

The solid-state imaging apparatus according to (1), in which

-   -   the infrared cut filter includes an organic material to which an        organic or inorganic color material is added.

(3)

The solid-state imaging apparatus according to (2), in which

-   -   the infrared cut filter has such spectral characteristics that        the transmittance is 20% or less in a wavelength region of 700        nm or more.

(4)

The solid-state imaging apparatus according to (3), in which

-   -   the infrared cut filter has such spectral characteristics that        an absorption maximum wavelength is present in a wavelength        region of 700 nm or more.

(5)

The solid-state imaging apparatus according to any one of (1) to (4), inwhich

-   -   the infrared cut filter is also formed in a region other than        the pixel region.

(6)

The solid-state imaging apparatus according to any one of (1) to (5), inwhich

-   -   the separation wall is formed by at least one of a metal film        and a Si oxide film.

(7)

The solid-state imaging apparatus according to (6), in which

-   -   the separation wall includes an organic resin having a        refractive index equal to or lower than that of the color        filter.

(8)

The solid-state imaging apparatus according to (6), in which

-   -   the separation wall includes an organic resin containing a        filler.

(9)

The solid-state imaging apparatus according to any one of (6) to (8), inwhich

-   -   the height of the separation wall is at least 100 nm or more.

(10)

The solid-state imaging apparatus according to any one of (1) to (9), inwhich

-   -   the pixels further include another separation wall separating        the photoelectric conversion unit for each of the pixels.

(11)

The solid-state imaging apparatus according to (10), in which

-   -   the other separation wall is formed integrally with the        separation wall.

(12)

The solid-state imaging apparatus according to any one of (1) to (11),including only visible light pixels as the plurality of pixels.

(13)

The solid-state imaging apparatus according to any one of (1) to (11),including a visible light pixel and an infrared light pixel as theplurality of pixels, in which

-   -   either the first optical filter layer or the second optical        filter layer in the visible light pixel is formed by an infrared        cut filter, while the other is formed by a color filter.

(14)

The solid-state imaging apparatus according to (13), in which

-   -   each of the first optical filter layer and the second optical        filter layer of the infrared light pixel is formed by a color        filter that transmits infrared light.

(15)

The solid-state imaging apparatus according to (14), in which

-   -   the two color filters in the infrared light pixel have such        spectral characteristics that the transmittance is 20% or less        in a wavelength region of 400 to 700 nm, and the transmittance        is 80% in a wavelength region of 700 nm or more.

(16)

The solid-state imaging apparatus according to (15), in which

-   -   the first optical filter layer and the second optical filter        layer are color filters of the same type.

(17)

The solid-state imaging apparatus according to (15), in which

-   -   the first optical filter layer and the second optical filter        layer are color filters of different types.

(18)

A method for manufacturing a solid-state imaging apparatus including aplurality of pixels arranged in a pixel region,

-   -   each of the pixels having:    -   a first optical filter layer disposed on a photoelectric        conversion unit;

a second optical filter layer disposed on the first optical filterlayer; and

a separation wall separating at least a part of the first optical filterlayer for each of the pixels,

-   -   the method including:    -   forming the separation wall;    -   forming the first optical filter layer; and    -   forming the second optical filter layer, in which    -   either the first optical filter layer or the second optical        filter layer in at least one of the pixels is formed by an        infrared cut filter, while the other is formed by a color        filter.

(19)

An electronic device including a solid-state imaging apparatus includinga plurality of pixels arranged in a pixel region, in which

-   -   each of the pixels has:    -   a first optical filter layer disposed on a photoelectric        conversion unit;

a second optical filter layer disposed on the first optical filterlayer; and

a separation wall separating at least a part of the first optical filterlayer for each of the pixels, and

-   -   either the first optical filter layer or the second optical        filter layer in at least one of the pixels is formed by an        infrared cut filter, while the other is formed by a color        filter.

REFERENCE SIGNS LIST

-   31 Solid-state imaging apparatus-   32 Pixel-   33 Pixel region-   51 Visible light pixel-   52 Infrared light pixel-   61 Semiconductor substrate-   62 Photoelectric conversion unit-   63 Infrared light cut filter-   64 Color filter-   65 Separation wall-   66 Color filter-   67 Microlens-   301 Image processing apparatus-   313 Image sensor-   5001 Electronic device-   5013 Image sensor

What is claimed is:
 1. A solid-state imaging apparatus comprising aplurality of pixels arranged in a pixel region, wherein each of thepixels has: a first optical filter layer disposed on a photoelectricconversion unit; a second optical filter layer disposed on the firstoptical filter layer; and a separation wall separating at least a partof the first optical filter layer for each of the pixels, and either thefirst optical filter layer or the second optical filter layer in atleast one of the pixels is formed by an infrared cut filter, whileanother is formed by a color filter.
 2. The solid-state imagingapparatus according to claim 1, wherein the infrared cut filter includesan organic material to which an organic or inorganic color material isadded.
 3. The solid-state imaging apparatus according to claim 2,wherein the infrared cut filter has such spectral characteristics that atransmittance is 20% or less in a wavelength region of 700 nm or more.4. The solid-state imaging apparatus according to claim 3, wherein theinfrared cut filter has such spectral characteristics that an absorptionmaximum wavelength is present in a wavelength region of 700 nm or more.5. The solid-state imaging apparatus according to claim 1, wherein theinfrared cut filter is also formed in a region other than the pixelregion.
 6. The solid-state imaging apparatus according to claim 1,wherein the separation wall is formed by at least one of a metal filmand a Si oxide film.
 7. The solid-state imaging apparatus according toclaim 6, wherein the separation wall includes an organic resin having arefractive index equal to or lower than that of the color filter.
 8. Thesolid-state imaging apparatus according to claim 6, wherein theseparation wall includes an organic resin containing a filler.
 9. Thesolid-state imaging apparatus according to claim 6, wherein a height ofthe separation wall is at least 100 nm or more.
 10. The solid-stateimaging apparatus according to claim 1, wherein the pixels furtherinclude another separation wall separating the photoelectric conversionunit for each of the pixels.
 11. The solid-state imaging apparatusaccording to claim 10, wherein the other separation wall is formedintegrally with the separation wall.
 12. The solid-state imagingapparatus according to claim 1, comprising only visible light pixels asthe plurality of pixels.
 13. The solid-state imaging apparatus accordingto claim 1, comprising a visible light pixel and an infrared light pixelas the plurality of pixels, wherein either the first optical filterlayer or the second optical filter layer in the visible light pixel isformed by an infrared cut filter, while the other is formed by a colorfilter.
 14. The solid-state imaging apparatus according to claim 13,wherein each of the first optical filter layer and the second opticalfilter layer of the infrared light pixel is formed by a color filterthat transmits infrared light.
 15. The solid-state imaging apparatusaccording to claim 14, wherein the two color filters in the infraredlight pixel have such spectral characteristics that a transmittance is20% or less in a wavelength region of 400 to 700 nm, and a transmittanceis 80% in a wavelength region of 700 nm or more.
 16. The solid-stateimaging apparatus according to claim 15, wherein the first opticalfilter layer and the second optical filter layer are color filters of asame type.
 17. The solid-state imaging apparatus according to claim 15,wherein the first optical filter layer and the second optical filterlayer are color filters of different types.
 18. A method formanufacturing a solid-state imaging apparatus including a plurality ofpixels arranged in a pixel region, each of the pixels having: a firstoptical filter layer disposed on a photoelectric conversion unit; asecond optical filter layer disposed on the first optical filter layer;and a separation wall separating at least a part of the first opticalfilter layer for each of the pixels, the method comprising: forming theseparation wall; forming the first optical filter layer; and forming thesecond optical filter layer, wherein either the first optical filterlayer or the second optical filter layer in at least one of the pixelsis formed by an infrared cut filter, while another is formed by a colorfilter.
 19. An electronic device comprising a solid-state imagingapparatus including a plurality of pixels arranged in a pixel region,wherein each of the pixels has: a first optical filter layer disposed ona photoelectric conversion unit; a second optical filter layer disposedon the first optical filter layer; and a separation wall separating atleast a part of the first optical filter layer for each of the pixels,and either the first optical filter layer or the second optical filterlayer in at least one of the pixels is formed by an infrared cut filter,while another is formed by a color filter.